The mining drones seem quite capable of mining the ore patches (https://mods.factorio.com/mod/vtk-deep-core-mining ). https://imgur.com/a/MVSt24t
It's not a big deal because it's very slow, but the drones seem a little overenthusiastic about what they're supposed to mine. I'll also report it to the other author and see if they'd like to implement a fix, too.
