I know you can mess with distant ped and distant vehicle settings:
distant_peds.xtbl
distant_ped_spawn_parameters.xtbl
distant_ped_colors.xtbl
distant_vehicles.xtbl
distant_vehicle_traffic_types.xtbl
distant_vehicle_spawn_parameters.xtbl
distant_vehicle_colors.xtbl
These LODs were added in SR2 because of aircraft implementation. They are effects, as opposed to individual vehicles/NPCs.
-distant_peds.xtbl
might allow you to swap out it's model (cmBod_simple01.cmesh) with a another .cmesh.
-
Maybe you can do the same with distant_vehicles.xtbl.
-distant_vehicles.xtbl also suggests there were initially meant to be distant boats. It's model (boat_medium.smesh) doesn't exist in the final release, but again, you
might be able to swap the model with another .smesh.
You will need to copy everything from under <TableTemplates> and paste it under <Table> for it to have a
chance of working.
I would approach all of this with caution, due to the infamous "
Freezer" bug. Keep a backup of the save you're using.