thanks for the tips, though given how much I hate the collecting.................................................................................. maybe i will find a system with like 16 planets and terraform all of them, i can collect and upgrade all in one place and get ridiculous amounts when i do so. I still prefer gas giants though....... actually, since there are apparently galaxy wide structures, maybe i should wait and have them be my mineral collection. i would point out though how odd it is to have more stars than gas giants. Honestly, I think there should be about twice as many gas giants as stars if we are aiming for realism. Our own solar system has 3 right.
Terraformed planets can still all be collected from when viewing a cluster. So you can spread them over multiple galaxies and still collect all with one button. Once you have upgraded all large extractor planets to a high level you can also usually move on to another system and forget about the previous one. Just favorite your cluster and current system. When you need to collect, switch to cluster, collect all, switch to system, continue building\upgrading, repeat.