I really dont have an opinion on this but it makes me wonder, with all the ppl asking for it and how much of a role it played in WWII, why hasn't it been added? There's got to be a reason, so of it hasn't been added yet, it might not be added for a very long time.
Because Skuzz put a cap on how much ordy would be allowed per aircraft... b-29 is WAY over that...
Let's put this into perspective.
B-17: (Short range missions, max bomb load ) 8,000 lb (3,600 kg).
B-29: 20,000 lb (9,000 kg) standard loadout.
It would throw game balance out the window, and would be abused. It's max altitude and speed at that alititude would be disrupting, almost invincible at alt. And 20mm tail gun... well... self-explanitory.