So in the absence of actually MUSHing, or having energy for it, this is the kind of thing I have been writing:
After The Collapse Quest
I did try running a strategic scale quasi feudal space admiral thing on the same forum previously, that I prematurely bailed on because I lost motivation and it was becoming a pain to write. That one hit 245 pages and was much more popular but does end mid plot:
You Are: A sector admiral of a strained imperium
Really not the same kind of thing as MU*ing at all but it goes some way to scratching the RP itch whilst also being more forgiving of me being eaten by work for a week at a time. Also it lets me try out my own settings and explore them which I find a lot of fun.
On the other hand I have been writing literal novels worth of terrible sci-fi web fiction in a choose your own adventure format and feel somehow guilty for this.