Snowfalcon2 #3849 and rh200 #3809 comment on poor accuracy of using signal strength for location. Agreed, and uncertainty in the aircraft's antenna gain degrades it even more.
Exactly. I doubt its a perfect omni-directional antenna. Heading/pitch/roll will affect the radiated power hitting the satellite, as the direction of the antenna on the aircraft changes.
That can be modelled however. I suspect there are some very clever people and alot of CPU cycles being burn trying to model possible flightpaths based on the data available.