i somehow can place the mk2 on top of the old ones, not instead of, just "on top", two buildings sharing the same space, noticed when i wanted to remove mk2 drills.... nothing to do with their recent update, prob an ancient bug
Even weirder when i try to replicate the bug it doesn't work right away, i have to make a blueprint of the drill with modules in them, paste on top of mk1, and... they magically share the space
Aaaand just to be an ass about it the game doesn't have me witness the same issue in different ore patches. Prob a non issue, i only noticed because i needed mk1 drills to make mk2 ones and the count wasn't right