I expected this would place a floating slab in the block above/below the one I am looking at, kind of like what you can do with other blocks, but instead it just disables it entirely.

Hahah fair enough thanks for considering it!

It is intended to be like that in a way, as otherwise the behavior you explained would give the player the ability to place slabs where they wouldn't normally be able to.

And also the primary audience of this mod is people who are doing some form of spawn proofing or similar with slabs, and want to avoid it forming double slabs while slabbing away the floor

Ah fair enough. Thank you!

Out of interest, would it be within the scope of this mod to provide an option for this? Or is this supposed to be one-off and low-scope?

Out of interest, would it be within the scope of this mod to provide an option for this? Or is this supposed to be one-off and low-scope?

Hmm not sure, I think it might be fine, I'll implement it when I have the motivation (probably within next month)