The crafting thing is nice, but I've always had an idea for a resource pack that detects when the Player places a doubleslab and replaces it with a regular full-block.

I tend to build a lot, and when I run out of fullblocks I just start using slabs. I thought it'd be cool to have a datapack that makes it so that when you place a doubleslab, that specific doubleslab is turned into a fullblock.
This doesn't mess with crafting. This pack also does not affect Smooth Stone Slabs, due to their unique Slab texture.





This also allows you to now use double-slab blockstates as custom blocks, if you want*.

The only issue with this pack is that if you place a doubleslab against a non-full block(Ex. End rods, torch, etc) it might not get hit by the raycast and will be missed.
You may be saying "Don't use raycasting then and just use Fill commands" and you may be right, but this has been set up so that the Doubleslabs can still exist, except they can only be placed with commands. This is so builders/datapackers can use custom double-slab textures. There is a method to my madness.



*Adding this datapack to BONEE-CB about doubles the amount of blocks you can add using the Engine.