I know this is a big ask, because slabs would have to be completely overhauled but it would be so awesome I had to suggest it. it would also make a better way to "cut" redstone lines.
Edit: I have been thinking about this recently and have come up with a less complicated way to implement this feature. A block state could be added to redstone components similar to "waterlogged", possibly called "slabbed". It would probably apply to redstone dust, repeaters, and comparators because they visually only take up half a block anyway. If the player tries to place a slab in the same block as one of those components it will become "slabbed" rendering the top slab and changing the top of the block to solid making it able to support other blocks like redstone components.