Basically, i suggest a creative mode where u could manually modify and save maps at will, placing and removing items, structures and natural stuff, unlocking resarch and edit events.
Then, start a new colony on that map.
This could open the creation of scenarios, easier/harder starts or also simply crating a test world where u could test stuff that are endgame with little effort.
Well Technically there is a "Creative Mode" You Can turn on Dev mode then god mode you have access to everything you can build and it builds it without resources or work and allows you to deconstruct everything as well. Also if you look in some of the dev tabs you can set terrian spawn in items and some other things as well.
Yeah what you're suggesting is basically "Let me cheat with stuff", so dev mode is the way to go.