Just dropping by to say thanks for this thread! I just did this swap, including moving the CAN wires to the new pins. Everything is working as expected, and the new unit is far better than the old 2010s-Camry-looking unit that the car came with.
I bought a Yaris Cross head unit from the UK off eBay (86140-YP032) - it cost about AUD500 shipped to Australia. It's now installed into my Dec 2021 first gen GR Yaris.
Re-pinning the middle connector was not particularly enjoyable, working out how exactly the connector comes apart was a bit nerve wracking. For the next person that attempts this - the connector is made of 3 or 4 layers in a sandwich, each row of pins is one layer. Each layer has a collar on the front that must be VERY GENTLY pried off to release the pins, which then slide out the back.
Prior to re-pinning, the vehicle data (fuel consumption) was not present, after moving the pins it became available. So i can confirm that moving the wires does restore at least that functionality. My dash display and steering wheel buttons work normally, but i'm not sure if they also did prior to moving the wires in the connector.
In my car the volume level seems adequate with the new head unit, but i haven't actually been for a drive yet to confirm.
The software on the new head unit seems pretty old, it has a 2023 date. I'll attempt to update it sometime in the next few days.