Quote:...t doesn't sound like, after I create my 10 regions of selection, that I can pick one of them and edit it as if it was just created...
Maybe you need to start looking at something more advanced such as saving individual selections to channels. https://docs.gimp.org/en/gimp-selection-to-channel.html
Slows the workflow down but at least you can go back and add/remove a selection as required.
Once in the channel dock and restored a selection remember to go back to layers and activate the layer you are working on. Always save your work as a Gimp .xcf file and layers + any selections / paths / guides etc are saved with the file.