Being able to split secret rooms into two types, having a door as the entrance vs. having solid blocks for the entrance allows for certain rooms to be safe spots for players that they can easily see. Currently, secret rooms on B2 and below are hidden with solid blocks while secret rooms on B1 have doors in front of them. If I can specify whether a room will have a door or solid block for its entrance, it can help with designing the dungeon since I would like some place a player could rest on the final floor while having hidden rooms with spawners around the dungeon to discourage them from tunneling in.