I'm not sure what you're saying regarding On1's Photo Raw. The editing is non-destructive but are you saying I cannot get back to the original master after an edit and leave the module?
With On1 Photo Raw all non-destructive with edits stored in catalog and in sidecars.
It is in Affinity Photo that does not work that way when you leave the raw module to go to the photo editing module, the app renders the raw edits. So you can not go back and have the same full range of capabilities if you want to change the way you did the basic raw editing.