For me this approach should be the easiest way and give me the best result. A simple plastic shirt taped just under the gunwale net tube should eliminate any over spray.
The top is even more straight and fair than the hull so I just need to fair in the taping. (the way I do it is very quick and easy.)
Once the shop is tidy changing it into a spray booth takes around 5 mins.

I know that the voices in my head aint real,
but they have some pretty good ideas.
There is no such thing as a quick fix and I've never had free lunch!