That's a workaround that doesn't solve the core problem. With any package, you can open a JPG, edit it, and save it to a new name (or archive the old file and then save to the old name). If, after you have made your changes, you decide to make more changes, now what do you do? You can open the edited version and make more changes and save it, taking the lossy compression hit once again. You could open the original file, make all the changes you made the first time, and then make the new changes. Neither is a particularly good solution.
My recommendation is that, regardless of what package you use, if you are going to work with a file in more than a trivial way, you save your changes in a non-lossy compressed format. Then you can go back and edit the file as many times as you'd like without concern for compression induced image degredation.
It's also best if you can also make those changes in a way that allows you to selectively tweak or undo your changes. With pixel editors, that is typically done by using layers. With metadata editors, it is done by just changing your changes back. The main thing is not to make direct pixel edits and save in a way that doesn't allow you to undo or tweak those edits later. I don't think you have to be dogmatically pure with this approach with every single file you ever touch. It's just good practice that can save you work.
