A dodge skillsoft still seems maybe a little too powerful, but I don't think it would be too bad. Ultimately it would depends super highly on stats, so it could be useless if you don't have the stats for it.
A theft skillsoft I think would actually be really cool, and could make using taking things or planting things on people as a way to push plots forward way more accessible. It gets my support.
On the IC side, if these are added, I'd want it thematic. Maybe they are all illegal, hard to find and more expensive. I can't see the city wanting to allow the legal sale of skillsofts that are the bread and butter of the elusive thief. Not openly at least.
Heck. Maybe it's an expensive and very difficult tech roll to turn an existing soft into one of these. If you want one, you need to get one made. Find a character who knows how. Fork out a lot of chyen and get difficult equipment. More work for tech types.
I imagine there are lots of ways to handle this. I'm just not a fan of seeing them in stores really.
The thievery soft I actually hate the idea of because an optimized character who didn't have the skill before slotting a platinum would be a nightmare shrouded and doing their thing. If they're set up for it then it has the lowest risk using the thievery soft out of the three suggested here.