Hi, sorry, I've been meaning to rework some of this.
In theory, it will save and exit Wall mode when you complete the circuit . Now, unfortunately there's a lot that can go wrong, and the system isn't realizing you've completed your walls, and you're stuck with no way out. I feel shame when I think of you standing in your apartment , with your new layout complete, unable to proceed.
I'm trying to find time to get like 3 hours this week to make a new build, it's easy for me to just add another menu button as an override to force the completion state. I'm a circus performer as my main career and this week is really crazy with rehearsals for a new production. Normally I could have just added this feature as soon as I saw your comment, but it might have to wait another day or two.