Hatches are pretty neat, but one thing I hate about them is that whenever I open one, I always lose ground - which seems to confuse NPCs as well. So... what if we allow platforms to be build on the same tiles as the doors and show up underneath them? This way, opening a hatch wouldn't always mean losing ground, allowing the player to walk on the floor like normal.
Doesn't seem that hard at all. All it would take is to make an exception where platforms behave as if the hatch isn't there while they're being placed.