>>718429449 (OP)
Not with any mods that currently exist. The problem with starfield is that there's no singular part of it that's good enough to enjoy. Skyrim was a solid vanilla game that happened to be the perfect sandbox for modding. Starfield doesn't have that at all. There's nothing to build off of. You would need to alter the game itself, not mod it.
>>718431240 is right. Giving the source code out is the only thing left to do. It probably wouldn't even be a bad business move because if people modify it into something good, the IP will gain value. I can't imagine they're earning much in sales at this point.