This is not a houserule board, but I can’t help it.
“Does not help Moscow.”
Yes it god damn does. The first time you SBR Mosocw you’re taking off from Eastern Poland. Maybe the second time, too.
“Does help Calcutta.”
Not really. Bombers are probably coming from a Kwangsi air base after J2. The only time it’d help them is on J2 itself.
Speaking of which, I usually don’t bomb Calcutta. The potential loss of a strat bomber sucks, and they’re not building more than 2-4 units a turn anyway after UK1, so the first six damage doesn’t matter at all. And then just a couple turns later, their income is so low (2-7/turn) that they’re not building anything that matters much anyway. This is only a very minor influence, but it might matter: if you bomb it, you’re bombing what will be your own factory.