Not all Cblack feminized characters end well, although in most cases the ones who meet bad, or at least, less-than-desirable endings are not the main character, but an antagonist who ends up feminized later on. Oglethorpe in "Ghost Story," Circe's agent in "A Second Chance," Amber in "A Tangled Web," Jaz in "Ariel Redux," Paul in "Opportunities," Hawthorne in "The Curse of Erzulie-Dantor..." Chip in "College Life/The Story of Chip" is an interesting case, because although she gets into a cushy situation at the end, it could be argued that she is still being used by others and has no real agency, so she's in denial.
Now, the thing about Kim is that she's pretty much the villain of the story from the very beginning. CBlack has had characters who are hardly lily-white end up in good situations, but they weren't outright villains and the people they hurt ended up in good places too.
But there are still a lot of loose ends and Chekov's Guns around, and the story could take an unexpected turn sometime. For instance, what about the two manipulative sisters, Gloria and Lola? What about those black market super-hormones? What about those mob bosses who are looking for Kim? What about Serena, who appears to be the only person who actually likes Rex?
I think the most likely ending for Kim is to be put to work paying back her debts to the Mob... on her back, sorta like what happened to Paul in "Opportunities." The odd thing in that case would be that possibly for the first time in any CBlack story there would be no TG character with a positive outcome at all... unless another one is introduced at some point.