Hi Derek,
You are not alone, I am about 15 years behind you and I find that lose these things as well, especially if I do not do them frequently enough. Keep plugging along!
To help with your problem, I highly recommend that you take a look at the RAW Power 3.0 user guide. The developer, Nik Bhatt, has some excellent descriptions of how to access files on your computer and images in the Mac Photos app. He also has links to a couple of articles he wrote that provide additional detail describing how RAW Power interacts with your Photos library both as a stand alone app or as an extension within that you can access from within Photos. It would be good to understand this because Apple “constrains” how RAW Power can interact with the Photos in your Photos library.
I am far from an expert but assuming that what you want to do is view these reworked images in RAW Power but leave them in Photos here is what I would try. Go to the File menu and select the New Photo Library window. This will open your system Photo library in RAW Power. You should then be able to use the RAW Power browser to find your reworked images.
I haven’t figured out how to upload figures to this forum yet but if you need some screenshots I will see if I can figure out how to do this and provide some.
If I have misunderstood your intent let me know!