mattjohnsonboston wrote: … If I go back into an image with a third-party app to do some more edits I loose my previous edits.
I'm not sure I've done much re-editing, like that, but I just now messed around a bit, and here is what I see when I use GraphicConverter to edit pictures in Photos: In Photos I went to Edit>(...) and chose my GC editor. The picture opened there, and I cloned one chair to a different place, saved, and told Photos to save the changes. Then I again chose GC, and I got the changed chair. I cloned a mailbox on another wall, saved, saved changes, and both sets of changes were in Photos. I then used Photos' Retouch tool to erase the mailbox, yada yada yada, it all worked. When I Revert to Original in Photos, it all goes back. Image>Edit with GC worked the same way.
On the other hand, if I choose Image>Edit with Lightroom Classic, LRc doesn't "save," it rather offers Export, so I end up with a separate file.
So it may depend on how a specific editor handles the transfer. Have you tried others? i'm using Sequoia, but I doubt that this has changed…