Honestly if I had to say, it'd be the whole "your the heir to a megacorp and must go out to earn your inheritance" premise. I'd personally really love a more loose story option where we can choose our own background, like for example maybe we're a slumrat working our way up, or a freelance agent taking jobs where we can, etc. Obviously the whole game is built around being a Steeletech Heir so I highly doubt this will ever be considered outside maybe a mod or even TiTS2 if that becomes a thing. Something like CP2077 backgrounds comes to mind in practice tbh. Hell, even just like a questionaire style which you get to pick specific parts of your history and reasons for going on the rush.
I'm well aware this is extremely conflicting with how the game is built from its core, so I doubt this will ever be considered, but its easily my biggest gripe/criticism. I just really like playing the underdog and going from nothing to everything personally, and having a hard-coded background is pretty darn limiting for character rp.