Concerning the weathering of the G50 marking keep in mind that the original picture in the modeller (the one dug out by Foo'bar) shows a completely weathered skin where obviously the weathering has been applied over the paint + marking layer before merging layers of the skin.
In the last screenshot the marking are of the automatic type as we know them from Il2 and are applied over the basic skin. To avoid to a certtain degree the effect of "newly repainted squadron markings" the markings themselves are made a bit transparent: you can see the weathering below the 'paint" of the marking!
It is certainly not a bug, more like an unfortunate feature

. To avoid this it would be needed to have the engine applying the weathering after the selection of the auto-markings for this flight...this implies a certain layering structure of the skin which can be applied at starting time by the engine.
Maybe it is intended, as the progressive weathering has been touted a while ago by Oleg, but probably considered as a detail to deal with later!
JV