It's not that I don't want to go with Emacs or Neovim. Rather, I want to explore what else is out there.

As for Kate, thank you for its endorsement! I've tried Kate since making this post and it^[Together with KDevelop. Though it has to be noted that KDevelop IIUC seems to rely on Kate for this functionality.] has been the only one which has yielded a desirable result. I can wholeheartedly attest to its quality.