Honestly, why do you actually set
popup_exclusive when you do NOT want to use the popup exclusively?
OK, ok. I now read the docs. But it seems not to be intended anyway. Exclusive should mean that this popup is receiving the attention... and nothing else... (that is why it doesn't hide when you click elsewhere). It behaves like a modal dialogue.
Maybe just arrange the WindowDialogs without Popup so they can all be accessed? (Enumerate open controls an rearrange when more will open.)
Maybe a screenshot would help to understand what you exactly want to achieve.