After reading through all the post so far, good work guys, liking the different versions I am seeing too, *thumbs up* congrats to all involved, loving the radar diiscussions too
My impression of the shadow related fps thing would seem to me that the game cannot processes detailed shadows travelling at high speeds and altitudes over undulating maps/terrain with trees, buildings and such adding to the processing complexity, hence why turning shadows off is good.
I have yet to try the newer ones in my old 4.10 UP game, which are newer than when I did have DBW working. But I think I damaged the the DBW & DBW1916 sfs files from my external HDD storage (5 year old exterall HDD with some bad sectors, I tried to copy in DBW backups over and also to replace the damaged files I thought were broken, but no luck, and my separate DBW back up is broken too) - so I can only UP or Modact selector options for me now, or fly stock 4.12 (as I am repeatedly having no luck finding and dl-ing proven working versions of the 14.12.1 Int from any of the main IL2 linked sites M4T, 1C, A&A yet.
It seems since loosing my internet connection in '12, I have been doomed since then to struggle with the UK's totally crap network spoiling most chances of my trying to update IL2, hell, when 4.12m came out, that took 12 or so downloads to get one that actually unpacked correctly & worked as suppossed. - Maybe Russia is purposefully corrupting links since the 'Operation Ukrainian' problem became a thorn for them in the eyes of all around them...?