First of all, awesome mod! I wanted to post a suggestion to CoI about this and then saw that there's a mod for it. Many thanks! :-)

Is it possible to have a "Max layers to excavate" zero so that it doesn't dig down at all? When mining the ore from a mountain, I prefer to start at surface level only and dig down later or maybe even not at all.

Thanks!

I’m not sure what you mean. Max layers to excavate = 0 would mean no designation at all (no thickness). If you want to stop at sea level and ”not dig down”, you should use elevation limit = 0.