Additionally, when you do the Selection trick, left mouse button only pans the selection.
You can't finalize the selection, Esc or Enter does nothing, you have to do some sort of operation like change tool or something.
With that I had to try something... with Lasso Selection, started panning and drawing.
Eventually if you keep doing it for a long enough time, memory usage starts climbing a lot.
First it's only few MB/s, do it long enough and it's almost 100MB/s and my record was about 8GB of memory being used
After finalizing the selection, paint.net still used over 1GB. Even if you close all images it still uses that amount.
The Selection finalizing not being possible is a bug? Selection overuse should be something no user should ever encounter.
You have to build the selection for a minute+.