Let me know when you are going to push this, or send me a proof of it please, so that I may see what you changed. I would specify the QHeader for 2.10.x for this, or whatever guys version was used in 2.10.0->2.10.2, and make that an exception. If people want to open a 2.10 quest and re-save it in 2.50, then they can have the fixed pattern. No reason to break quests that are years-old, in the process.
Most of the 2.10 questmakers are no longer around, to correct design flaws that rely on behaviour that was perceived (at the time) to be proper.
I do remember quests in 2.10 that had enemies in walls as triggers, inside dungeon rooms. Sorry. People did this.
Someone should check if 1.92.x Wizzrobe behaviour was such, that they could spawn in walls, too. I think that spawning in walls became a problem around the time that fire or bat Wizzrobes were added. If any of you have a system that can run 1.92, please let me know; as otherwise I will need to fire up an emulator to check this.