So I haven’t tried this a second time, but considering how it went the first time, I would assume it can happen again.
I was going around Parallax on Forge to measure the distance of movement, and I accidentally boosted to outside the boundaries. I couldn’t go back in for some reason(Some reason being invisible wall), and I got killed for stepping out of bounds as a monitor. As I’m posting this, I spent around 3 minutes just stuck unable to respawn.
Also, going back into the map having quicksaved, I can’t move around or do anything, so I’m left with an unedittable map, I guess. Luckily, all I did was just erase the preset items, so no effort really wasted.
So yeah, not sure if it’s a minor glitch or an oversight in design.
Update: I confirmed it a second time, dying as a monitor outside the main boundaries of the map doesn’t let you respawn into the map.
Update 2: Unless you have a respawn point set, apparently. Seems odd, especially since someone would want to remove all respawn points to start forging from scratch. False alarm, I guess?