I don't have a Mac and don't know if you've tried this, but you might still be able to run the standalone programs directly from the installation directory for

I don't have a Mac and don't know if you've tried this, but you might still be able to run the standalone programs directly from the installation directory for making atomic edits to photos, then import those as new layers into your project. It isn't as good as using them as plugins, which lets you readjust settings on-the-fly, but it has worked for me as a hobbyist.