Here's some videos for better reference concerning the AI handling. I suppose after testing multiple vehicles together, the wheeled ones do fair better than the BMP, which seems like the only one that gets stuck. The M-113 might be the same as well. Maybe because of the tracks? I also tested the RHS BMPs to see if maybe its an ARMA problem, but they seem mostly fine.
Vanilla Control
GM Vehicles
BMP-1

Given that this happens in vanilla arma buildings too... might be something that can be fixed more widely. Assuming BI cooperates...

Same issue with the M113, and to a lesser extent the Fuchs. Vanilla vehicles do show a similar behaviour, but the difference is that they have a tighter turn radius which makes it more controllable. Note that boats seem to handle very differently to amphibious vehicles.

Confirmed the issue

Issue has been fixed

License plate numbers set through the GM functions can now also be obtained by using the getPlateNumber scripting command

The function to set it is: [vehicle player,"Number you want to set as String",0,1] spawn gm_core_vehicles_fnc_vehicleMarkingsUpdateAttributes;

There is a problem trying to get into the East German medical Ural via the backdoor into where the stretchers are located. I've tried trying to enter via the scroll wheel but it doesn't give me any option to do so. I've tried this with and without mods. I can only spawn inside the compartment.

test