That sounds much like the way GIMP operates on the Mac, or at least the way its UI used to work. I found that totally alien at first, coming from windows to Mac, but got used to it even though I preferred the all in one approach as I knew EXACTLY where everything would be.
I should think that as long as it came (if possible) with an easy to use/instant access window/panel manager or simple/user created system of shortcuts that allowed you to flip between Pinegrow PANELS/ and/or, Pinegrow SCREENS - and if PANEL positions could be remembered, that would be fantastic!
Even if you had to click between windows (and screens) people would complain about the inconvenience of this but HEY! you still end up with MORE SCREEN REAL ESTATE.
I just use my old 17" MacBook Pro, so I have one screen.
If Pinegrow could do this, I would actually use a second screen!
I don’t bother with this for any other app.
when paired with Atom or VSCode , with everything in dark UI mode it can be pretty confusing for me sometimes - without the other apps I am using at any given time, so
Alt+Tab are my saviours to flip between apps.
SO with this shortcut to do that to flip between APPS,if there were then other shortcuts to flip between PANELS within Pinegrow, which then allowed me to Alt+Tab back to the browser/file browsers/FTP APPS etc, I should think that you would be onto a serious winner.
But I am so terribly easy to please… providing everything is done MY way