So I know that vertical slabs have been rejected, but I have a compromise, if a vertical slab block on its own (in survival) can't be a thing. Instead of adding a whole new block, why not make a new setting for the debug stick to modify the slab. What if by left clicking with a debug stick could switch to vertical facing mode for a slab. Then, in survival of course, you would not be able to build with it, but anyone building in creative could, with the help of the debug stick.
So I know that vertical slabs have been rejected, but I have a compromise, if a vertical slab block on its own (in survival) can't be a thing. Instead of adding a whole new block, why not make a new setting for the debug stick to modify the slab. What if by left clicking with a debug stick could switch to vertical facing mode for a slab. Then, in survival of course, you would not be able to build with it, but anyone building in creative could, with the help of the debug stick.