Gptel has been working great for me. I'd be interested in checking this out but I only have so much time to set up and test new tools. What features would make it worthwhile to switch from gptel?

You don't "switch" from gptel as this package solves a problem of a different dimension. Gptel is still great for tons of other things, even though it's not suitable for "project context-wise" LLM workflows.

I am using macher for small edits on a codebase with gptel: https://github.com/kmontag/macher

The package define a list of tools that gptel can use to inspect and edit a project. The tools are packaged as a preset so all you have to do is add "@macher" to your prompt to include the tools & update the system directive.