Only glitch is: the german accents like ä, ü, ö are not rendered in the game menus and in-game texts. This has been corrected in the 'Ahnenerbe's Optimized Widescreen for WAC 5.01'.
I wonder which files I must transfer to correct this [EDIT: see end of this post]
Else I can confirm the mod works perfectly, for example I have loaded an older setup like this:
WAC 2.0
WAC 2.15
WAC_Revert_UBoot_Interior (a mod from me)
Hotfix 2.15
WarAceCampaign_Sky_Fix
FlagMod
Ahnenerbe's Final Widescreen.
With this setup the game loads very FAST (an alternative to the slow WAC 5.01) and so the game plays flawlessly.
For the kicks, I will try to add the WAC 5.01 U-Boat Interiors to see if it works...I guess yes because there are far less decor objects in the 3D world to load
[EDIT]
To correct the german accents in Ahnenerbe's final mod, you need to download 'Optimized WAC5.01 WidescreenGUI 1920X1080 Ahnenerbe.7z' and take these files from it as a replacement in this mod:
C:\...\data\Menu\Fonts (all files, overwrite)
C:\...\data\Menu\menu_1024_768.ini (overwrite this one)