I don't know. I do not thing that any option settings affect the dialog box itself, Someone could switch modal off and experiment.  It would certainly make it easier to change something, Apply, and then try it out.  The is one place I would not feel obligated to follow modal-happy Microsoft.  (Too small, cramped dialog boxes designed for 400x600 screen is another.)

I have asked the same on at least one of the search dialog issues.  The search dialog for Notepad++ is not modal and works fine.

Also see #24039.