Regarding the 12 hour scenario, that's going to be a once a year thing, running too many of those really limits the overall design options, only so many physical ways to keep 12 hours of activity going.

I do like the idea of a Euro evolution event, not unlike our Pacific event where we started in Pearl and ended over Japan. Each frame, new planes, new resources, advances and losses per frame sets up the next frame, each frame triggers new start points and map configuration.
What do you think of something similar to last Pacific War but at Eastern Front. We have very nice set of VVS planes that have never participated in the scenarios: Yak-7b, Yak-3, I-16, Tu-2 - we need to use them...
Frame I: Operation Barbarossa 1941
- I-16, IL-2, T-34/76, Limited Yak-7b(*)
- 109E-4, Ju-87D-3, Bf-110, He-111, Ju-88, Panzer IV (short barrel version) Limited Bf-109F-4 (**)
LW Objective - destroy a set of VVS airbases, capture a set of V Bases
VVS Objective - damage LW, prevent from LW to gain air superiority
Frame 2: Stalingrad 1942/43
- Yak-7b, Yak-9T, I-16, IL-2; T-34/76, A-20, B-25, Limited: Hurricane, P-40B, La-5
- Bf-109F, Bf-109E, Bf-110, Ju-87D, He-111, Ju-88, Panzer IV, Limited 109G2
Frame 3: Kursk 1943
- Yak-9T, La-5, IL-2, P-39Q, A-20, B-25; T-34/76, Limited: P-40
- 109G2/6, Fw-190A5, Bf-110, Ju-87D, Panzer IV, Tiger I
Frame 4: Fall of Berlin 1945 (or other late war operation)
- Yak-9U, Yak-3, La-7, La-5, IL-2, Tu-2, B-25, T-34-85
- 109G14/K4, 190D/F, Me-262, Panzers, Tigers
(*) Yak-7b is good substitute to Yak-1. Note: Yak-1 is actually superior to Yak-7 in terms of performance having higher power/mass ratio.
(**) 109F-4 has more powerful engine in comparison to 109F-2 that was common at Eastern front.