Neg scans (grain with FP4+)

[GLS]

A qualified YES: Be sure you're sharpening a duplicate/copy and not the original...AND you may be better off sharpening with NIK because it's non-destructive until you confirm it. I usually avoid any sharpening at all with 35mm/Nikon.

Just FYI, if you convert your base image layer to a smart object then any filter you apply to it will be non-destructive, and can be edited or removed later. No need to rely solely on Nik plugins.

And while we're on the topic of edits best saved for PS, another option I can't sing the praises of enough is targeted contrast adjustments using luminosity masks.....