you can - but they dont work reliably in practice. Common issues include search match fails, missing commas in replaced items (model doesnt have surround context while replacing), and a few other error cases. This issues are much worse for scattered edits across a file from real world queries (ex: make this page look nicer). Patches tend to work fine for single line or extremely focused edits though - Cursor uses s&r/patches for single line edits:

https://github.com/x1xhlol/system-prompts-and-models-of-ai-t...

I wonder if it'd be feasible to have a much smaller model that could go in and correct these meshing issues that require simpler reasoning?

hm maybe but correction/issue detection is a much harder task for models. If you pipe back the errors in it could work, but personally still see Fast Apply as the better approach