Here is my log.lst. It was too long to post here, so I uploaded it to my mediafire. I was getting 50 fps in black death until the il-2 dropped its bombs, then I got 0 fps for the duration of the clip. Link: https://www.mediafire.com/download/c6qv5v5vc3d8jzg/log.lst
Your fps problems are caused by repeating java errors.
The troubles start when a vehicle gets destroyed:
[6:28:04 PM] INTERNAL ERROR: Can't open file '3do/Cars/OpelBlitz6700A_radio/summer/Damage.mat'
[6:28:04 PM] WARNING: object '3do/Cars/OpelBlitz6700A_radio/summer/Damage.mat' of class 'TMaterial' not loaded
[6:28:04 PM] INTERNAL ERROR: Material: Can't load 'Damage.mat'
[6:28:04 PM] Mesh 3do/Cars/OpelBlitz6700A_radio/summer/dead.sim not created
[6:28:04 PM] com.maddox.il2.engine.GObjException: Mesh 3do/Cars/OpelBlitz6700A_radio/summer/dead.sim not created
I dont have TFM-412, just trying to help so someone needs to take a look at the technics.ini and the files of that truck and fix the errors. It seems that some new vehicles dont have a destroyed version. A very easy way to fix this would be to change the techics.ini entries to the original damage model mesh of those trucks.
From the logfile these are the vehicles that cause problems, theyre part of the recently added Wflyer vehicles pack:
OpelBlitz6700A_radio
OpelBlitz6700A_medic_summer
OpelBlitz6700A_summer