I’ve been using the Nik collection for years. I have often saved images processed in the older versions (4, 5, 6, 7?) and I often save the results using the non-destructive option. When I open one of those images in the latest version of Nik, say Color Efex Pro, will I see the steps I took in the older version, and will they make sense?
Check out what the user guide has to say about it:
I consider the Nik apps to be destructive because they can’t handle RAW and need a new export in order to preserve some level of plasticity.
Editing an old export with a new Nik? Yes, that works, but I strongly propose you work with copies. of the old files. Not all apps can handle multi page TIFFs!