My setup is generally one large external monitor with 4 screens configured, and my macbook display off to one side acting as a separate display.
And this works until I disconnect the main display. All of the screens shift over to the new primary display - and I think that this mostly works OK, I have to say that that display is so small by comparison that I've not really looked at how I want to configure tangrid in that layout (that might be a separate Feature request). Anywa, when I reconnect the main display, things go haywire.
Windows that were floating, are sometime no longer floating and get wrapped into the autoflow (I have this as the default). That's not too hard to fix.
What's really weird is that on one of the screens I have a roughly 50-50 split. a tab stack on the left, and a single window on the right, after the display reconnects, there's still the tab stack on the left, but there are two sections to the right, one with my app window in it, and the other empty and really hard to get rid of.
Some combination of messing with other windows and switching screens seems to reset it - sorry, but I've not really worked out the specific set of operations that cleans this up.
Ideally I'd want everything to go back to how it was when the display is reconnected - I'll admit that I can see how this might be difficult, but at least no phony window blocks that you can't get rid of.
