Precisely that scramble was in a QMB+ with fulll smoke mods (usually FPS killer at effects = 2), 4.09 with 72 km horizon, water 4 on the river, trees = 2, complex mod clouds, lots of planes on the ground, 16 attackers, and 20 defenders... you see.
For other references, there uses to be used as benchmarck the default track "The Black Death" with the views as default.
There, my fps are sustained at 60, the max the monitor can show, with some minor falls to 45-50 when Il-2's attacks the vehicles convoy on the track, and only one serious slow down to 26 fps when the first 190 is downed, because as backkgrount there is the aerodrome full of smoke while being attacked. All this, with mods on on UI 1.1... Ultrapack 1.7 has different performance, looking a little bit better I think, but with a little bit less fps.