Don't overthink it. You do not have to mask the whole thing at once or cover all of the glass.
For a given rectangle, I would use eight pieces of tape.
Don't try to create that magic one piece does the trick solution.
I start by putting one piece in each corner, with a very clean cut on the end in the corner. The piece should be only slightly longer than half the distance to the next corner.
Then do another piece in that corner that comes back and only slightly overlaps the first piece.
Do the same for the other three sides, and spray with clear.
do enough of them to get both most of it done.
Then paint.
Bill