Glad you have found a way to share the Bomb Bay tank fuel with all 4 tank groups.
I am working on thoughts....
Re: workaround Bomb bay Fuel weight possibilities, and will share those thoughts in a less 'Public Way' than here in this forum.
We've been investigating this issue but unfortunately neither us, the testers or Thranda can reproduce this. If you haven't already done so, please submit a support ticket and send us your log.txt file.