Playing Drath and Alterians for a while I discovered an interessting exploit (or at least I think it is).
Biospheres, a structure that improves the planetary production by 10% and adding 3 to the plantes quality, can be razed and rebuilt like other structures. However, the bonus of 3 to the planetquality is NOT a bonus on first built only.
As a result you can max out all your planets to a quality of 72.
As the result is "slightly" overpowering id appreciate this to be fixed as iam too weak to resist the temptation