My scene is in mm and I'm experiencing this daily when loading multiple objects (or FP presets) via the Library browser in FP:
The dialog box asking if I want to rescale the objects from say CM -> scene units (mm in this case), only shows up on the first object. For the rest of the objects, this dialog box seems to be hiding behind the Library Browser and getting it to pop up in front so I can click OK seems random with me having to click all over the viewports or minimizing material editor (on my 2nd screen) etc.
Overall it seems FP dialog boxes struggle with my current 3 monitor setup. The dialog boxes are hiding all over the place and behind other windows even though max is the active one.
Can you do something to have them pop up on main monitor and "all ways on top"?