Google Photos will soon allow you to select the default app for editing RAW files.
Right now, when you try to edit RAW files in Google Photos, you’ll see a pop-up menu asking you to choose a RAW editing app or find one on Play Store.
Now there will be a separate “RAW Editing” settings page in the app, allowing you to enable editing in default app. Thus, when you press the “edit” button, you will immediately open the pre-selected app.
This page appeared inside app version 6.13 and is not yet listed in the settings.