In this question:
Should I allow a PC's spells to affect a very large space vehicle?
They ask about balance and how it relates to some mechanics from the 5th Edition D&D mod (addon?) Ultramodern 5e, and actually includes additional rules from Esper Genesis (a 3rd party source for space combat).
Or maybe even just dnd-5e-3rdparty (exact verbiage up for debate) to cover everything?