P: Ability to flatten edits without exporting or apply stacked changes.

I primarily shoot analog film photography and have used software like SmartConvert, Negative Lab Pro, FilmLab, and VueScan to all first invert and normalize RAW files from my camera before importing into Lightroom.  This is extremely wasteful and time consuming as the Lossless Compressed RAW files from my camera being re-saved into a de-moasiced TIFF increases the file size 4-5x, then to only re-import into Lightroom for final color adjustments, grading, dust removal, and sharpening.

I have attempted many times to do all of this editing within Lightroom and Photoshop but because my photos are inverted to begin with almost all of the controls become backwards, ex: exposure, contrast, white balance.

A feature in which I could apply a set of masks and edits, and then "flatten" those changes then continue editing with further edits being "stacked" on top of the previous ones would save me over an hour of time when I scan more than 4 rolls of film at once.