between 1.39.128.936 & 1.39.129.84 lod used for rendering FFV turret was changed from first resolution lod to view cargo lod - probably this change is connected with adding FFV abilities to copilots. This FFV behaviour is also present in 1.40RC
While in general that change should be praised it leads to some issues with different than regular FFV implementations like making soldiers sitting on tank or APC. Making more detailed view cargo lod with exterior could be valid solution but there is performance price for that as detailed interior & exterior need to be rendered at once. Beside that, it's easy to reach poly limit that way.
Therefore it would be nice to have ability to control LOD used for FFV positions with params lodTurnedIn/Out that are working fine with regular turrets.