Hey Peter,
Thanks, I’m not surprised.
As this project has evolved, polling is less a concern - my AppleScript daemon is happily chugging away. I wonder how one would actually measure it's drag on the system. I’ll presume your clipboard trigger is from an OS notification?
My bigger issue is the restricted communication to the floating window, and getting obscured by Quicklook, as mentioned.
And a wish list item - a window so small would be nice to drag it by clicking anywhere in the window, or with a modified click. I just found this tip about enabling that systemwide with ctrl-cmd-drag.
(TLDR:
defaults write -g NSWindowShouldDragOnGesture -bool true/reboot
). Works great.