First, it is important to say that disconnection of small battery can crack warranty for both batteries (small and hybrid one). It would be possible to update warranty for batteries anyway, but Toyota dealer can ask you to remove relay from small battery before warranty renew. Also Rav4 car has "weak" power supply from the small battery, so if you installed additional stuff (like relay, trackers, etc), then I recommend to disconnect small battery every night (other case you can get out of battery sometimes in the morning if left car for more than a day of two). Currently I bought external power supply (BPOWER 22800) and use it as power for tracker instead of battery in the car. The text below written before this remark.

 

Apart from trackers (passive components), I use two active components: first RFID relay instead of regular one to prevent power on petrol engine (for hybrid car) without remote control (that doesn't require to press button, so "keyless" relay) and second DC power off switch (that allows to disable power from small battery with wire minus and small battery located inside the trunk for the Toyota Rav4 5g hybrid). Apart from actually testing these two systems with my car for some time, I did check of OBD-II DTC codes (see below results). Someone suggested that no problems with these OBD-II DTC codes, because: ""Inactive" DTCs don't matter and can be safely ignored--they are just "in history" or "archive." All you need to be concerned about are "ACTIVE" DTC codes and warning lights or messages on the MID screen. You don't even need to clear inactive DTCs.".

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First I would like to describe results of testing these active parts in regular way usage (where I have 3 remote controls that are one is original for doors lock/unlock and additional for DC power switch (with buttons on/off) and one more RFID without button or better to say RFID have optionally used one button):

1. When stop the car. After I close doors of the car, then I wait for about 30 seconds and then press button "off" with the second remote control to disable minus of small battery (located in the trunk of the hybrid Rav4 5th generation car that is 2019+). I need to wait 30 second, because this is time for preinstalled simple additional alarm system to enable, but anyway good to wait for some seconds after doors-lock to be sure that all systems of car went sleep. Note that it is not required to turn off DC power off with the remote control every-time, so if in hurry, then can go as if regular car without additional systems just using one main remote control for closing doors (or not using any remote controls if key-less entry to the car at all, but I have no key-less entry system, so I'm using original remote control with buttons for my car doors-lock).

2. I can see that actually DC power off, because red alarm lamp on dashboard not blinking anymore (after DC power off by switch with the additional remote control).

3. When start the car, first I press "DC power switch" button "On" (at this moment back lights blinks for short time) and then I can immediately open the doors with the original remote control. I can turn on car immediately too and go, so no need to wait at all. The only difference (comparing with the original configuration of the car) that multimedia takes about 20 seconds to start after such "cold power ON" (and back camera doesn't work during this first 20 second before multimedia display started and it tells "loading" during this 20 second) that is longer than usually when "soft power ON" (that takes just few seconds). Anyway I can go immediately (if I don't need back camera) with the car and I don't need to update anything (so time and other parameters in place like it was before). If I start car first time in the morning, then usually I press once button of the RFID remote control (even this is not required, but for reability reasons good to do this if not used car for some time or if DC power switch was off). Before moving from P to D, usually I press gas pedal, so then I can hear engine working, and it means that car ready, so only then I move from P to D and start driving.

4. If I try to start the car without RFID, then it works (I can see "Ready" for Hybrid car and can start moving slowly until petrol engine try to start). It is not possible to start petrol engine without relay controlled by RFID enabled, so I see engine error on dashboard. I can turn off the car, take RFID remote control (say from home if forgot it) and then turn on the car and no any errors with the dashboard and everything works fine. However, some DTC internal errors would be recorded (see below), but inactive or achieve kind of errors (not displayed for dashboard at all), so then I can use OBD-II reader/tool to clear these internal DTC errors, but it is not required to clear it, so no problems if you don't have OBD-II reader/tool.

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More details about tests I did:

I. After removing "EFI-Main No.1" relay (not being used anymore by me) and then removing "IG2 No.1" (this one being used as RFID remotely controlled relay), and of course removed these relays separately of each relay, but not simultaneously, I had a lot of DTC codes like "no communication" between different modules: ((ECM) A (Archive (inactive) and Confirmed), TCM (confirmed), drive motor control module (confirmed), hybrid powertrain control module (confirmed), instrumentation control module (confirmed), navigation control module (Archive (inactive) and confirmed too), Data bus (confirmed), steering position sensor control module (confirmed), Adaptive Front light System (AFS) DTCs 2 (confirmed) that are B2415 [0xA415] and B242F [0xA42F], Electric parking brake C13A9 [0x53A9] (confirmed)
).
II. I clearned DTC codes (used "veepeak" for OBD-II).
III. Read once more after cleaning and after small test-drive and only one DTC code still appears: "
U0100(87) [0xC10087] Archive (inactive)
Data bus, engine control module (ECM) A - no communication
Status: Pending
". I found some data that describes what this code about. I think "Archive (inactive)" with status "pending" means that this is outdated (not actual anymore) error (or something "pending" till test results ready). When I visit dealer next time, I'll put back regular relay in place before and ask dealer to do diagnostic about this code (or maybe just to clear it, because maybe my scanner cannot clear particular this code). Active codes looks like this with my scanner: "Electric parking brakeElectric parking brake DTCs: 1 - C13A9 [0x53A9] Status: Confirmed", so status "Pending" means something different.
IV. Apart from relay, I used "DC power killer switch" (so to disable power from small battery that is in the trunk to disable minus from accumulator battery completely with the remote control). This time I tried to enable power and after that start the car with relay "IG2 No.1" disabled (so no RFID remote control with me like left it at home). As result, I got again a lot of similar errors like I had before:
(A) U0110 [0xC110] Data bus, drive motor control module - no communication, (B)
U0293 [0xC293] Lost communication with hybrid powertrain control module, (C)
U0100 [0xC100] Data bus, engine control module (ECM) A - no communication, (D)
U0101 [0xC101] Data bus, transmission control module (TCM) - no communication, (E)
Entry & start / Smart keyEntry & start / Smart key B2788 [0xA788]. Apart from this, dashboard shown me errors of PCS, BOS, Drive-Start Control.
V. I turn off the car, wait for about 30 seconds, then turn off DC-power minus switch.
VI. Back to the car with remote control for the relay "IG2 No.1" and turn on the car in regular way. The RFID remote control not required until petrol engine starts, so if enough power in hybrid system, then I would not see if RFID relay activated or not. The petrol engine not started yet.
VII. Read DTC errors. It is the list of errors described above in p.4. Clear errors. Read errors again. Only one exists "U0100(87) [0xC10087] Archive (inactive)" (described in p.3 above). Turn off the car. Disable DC power.
VIII. Enable DC power from battery. Unlock relay (press button once for RFID remote control even it is not required, but like said before first time better to do this, because other case RFID may not work after relay was disabled during night time or by DC switch off). Turn on car regular way. Read DTC errors if any. No errors (apart from one "U0100(87) [0xC10087] Archive (inactive)" , described in p.3 above).

Also I did safety test of my RFID relay: go to drive a little bit without RFID remote control in my pocket (left it home) and no problems, I could drive for about 10 minutes and returned home. Petrol engine works without problem. Looks like this relay only turns off after I disable minus from battery with "DC power remote control switch" (that works simple with on/off buttons on remote control, so without RFID) or can be disabled when I go away from car (but not always).
Also I had a chance to check if remote controls different for each device and yes: I cannot control "DC minus remote power switch" device with similar remote control from the other similar switch.

Overall I have next systems installed to the car that works together: RFID relay for "IG2 No.1", DC power switch with separate remote control (button), tracker connected to battery (that calls my phone (so to wake up me in the middle of the night  when DC power on or ACC (engine) on or optionally when car moves it can call too if configured), additional hidden tracker that doesn't require external power and located such a way outside the car for making harder radio signal suppression of it's GPS/phone-cell.

I'm not sure if RFID relay for "IG2 No.1" goes to disable state at all if power not disabled with the "DC minus remote power" killer switch (sometimes it happen after I go away from the car and sometimes not). It means that both required and better to press button once for the RFID remote control too before starting engine even this is not required (also think that when DC battery power off, then it means that not possible to open the car without keys by the CAN bus).
However, it is also possible to disable RDIF relay if pressing 3 times it's button, but I didn't try it yet to disable it with it's button.