Plus counting mined blocks with shape excavate doesn't work properly (setting max 90 blocks mines only a 5 blocks long 3x3 tunnel, instead of 10) and 180 blocks mine not evet full 7 blocks long tunnel.
How is it so random?

Thanks for finding the duplicated option, not sure how that ended up there.

I'm gonna look into the other issues mentioned

I opened the block counting as a separate issue - #67 . I am currently trying different changes in the code, but so far no luck.