Alright, another bug report for starters: games namesake, Il-2 is screwed up bad.
At least 1 loadout,
IL_2Type3M B 192xPTAB2_5
is wrong, game only has 96 PTABs option for 3M, probably a bug. But thats minor compared to the real problem - Il-2 model naming is way off in allpayloads.dcg
IL_2Type3M - named correctly
IL_2Type3 - named correctly
Il_2T - should be IL-2T, file is case sensitive
Il_2MLate --> IL_2MLate
Il_2MEarly --> IL_2MEarly
Il_2_1941Late --> IL_2_1941Late
Il_2_1941Early --> IL_2_1941Early
Il_2_1940Late --> IL_2_1940Late
Il_2_1940Early --> IL_2_1940Early
Il_10 --> IL_10
Also IL_2T (torpedo bomber) and IL_2I(heavy fighter, prototype only) are missing from allpayloads completely, though present in class.dcg
As a result, ALL Il-2 variants, even the ones correctly named have all their payloads at default in payloads.dcg. Meaning all of them are flying w/o a bombload, which, according to their pilots, never happened. I can upload a corrected version of the files if you want, but i suspect you had already made some adjustments yourself since 05 release and it would be easier for you to make adjustments yourself.
EDIT: As for your BoB campaign, i'll give my impression in a dedicated topic. 1 point though:
Imagine a set of say 9-12 big but minimal maps (you're meant to be fighting the enemy, not admiring the scenery) with some overlap covering most of Europe, allowing campaigns to move continuously from Normandy to Berlin for example?
Isn't that roughly what grandcampaign is already doing? I was under impression map transfer worked well in DCG, although never had the time to test it all the way from Poland 39 to Berlin 45.
EDIT2: Actually, speaking of eastern front and payloads.dcg almost all soviet bombers are flying empty. TB3, SB, Il-4, Pe-2, Pe-8, I-15 and I-153 which were mostly used as a ground attack craft by the time war started, U2 which was widely used as a night bomber. Also no soviet fighters double as multi-role by default (unless its player squad and you set a loadout yourself) although by mid 44 at least La series often carried bombs (they were preferred for the role due to extra survivability provided by radial engine)