Hey @Mad-Hatter my home planet pre 1.3 was turned into a rare exotic planet (the hexagon one) after 1.3 update. I have since come across several variations before completing the purge mission, there are still some versions I have yet to see. Just keep visiting dead, uninhabitable, airless etc planets, eventually one is bound to be a rare exotic. I had a spell where I ran in to quite a few consecutively system to system.
As for losing your homebase, not sure, last time I journeyed through the center was before 1.1 :3 You can get to the end of the purge mission, and choose to “leave” which will reward you with all the same stuff (rememberance tech recipe etc) but allow you to stay in Euclid. You can complete the purge later if you so choose, but it requires you to manually make your way to the centre (the new purge path now teleports you there regardless of location in the galaxy, should you submit to the atlas. Makes that permadeth trophy very attainable now! Refusing the purge, allows you to reach the centre the old school way, but doesnt deny you rememberance)
Sorry if im repeating myself. I only discovered this recently, I thought you got rememberance for doing the atlas path and birthing a star, spent weeks thinking my game was bugged and was avoiding the purge. Turns out you get rememberance from the purge, whether you reset or not. Those rememberance terminals are juuuuicy!