I work at Greptile and agree on all three criticisms. 1) is a bug we haven't been able to fix, 2) has to do with the high cost of re-indexing, we will likely start auto-updating the index when LLM costs come down a little, and 3) has to do with LLM speed. We pushed some changes to cut time-to-first-token by about half but long way to go.

Re: prompt engineering, we have a prompt guide if that helps, was that what you are getting at?

https://docs.greptile.com/prompt-guide