Just a side remark: The topic is terra incognita for me, but it’s nice to get a feeling of something new. It also “explained” why ‘Flip’ was available in FilmPack only, something I was curious about.
Orientation is written in two places. Try them both.
George
I also use VueScan, (and Lightroom) but there are a couple of long-running threads that PL does not properly support DNG. It does not support DMG from VueScan, The problem being a lot of museums, galleries, archives globally have standardized on DNG etc have scanned billions of old images to DNG. A DNG that almost everyone except PL supports 
Thankfully there are no lack of alternatives for all those archivists.
Yes, one is for the camera orientation and one is for the orientation of the image (RAW and/or built-in JPEG. On Canon cameras, te orientation can be set to adapt, be it on the camera’s or the computer’s screen. How these settings are reflected in metadata, I cannot say because i’ve not specifically tested tor these cases.
I am on holidays in Sevilla now. But when i remember one is in the exif and one in the makernotes. They both just tell the reading program what sequence to use reading the file. I think though not sure that PL is using the makernotes. Or the other way around.
George
I feed my raw files from a reprophoto of a negative - color or b&w - into Darktable’s Negadoctor tool which swaps the negative to a positive while taking care of color un-balance from the filmbase, among others. Negadoctor can be moved to an early point in the processing pipe line so the later introduced tools - initially Exposure - works directly as opposed to having its effect inverted. Over all, Darktable is a brilliant - free - raw manager with an advanced non-AI masking system. This is my choice as a disappointed PhotoLab7 owner, who has worked with all the leading brands of raw editors on the market.
If I have a pixel-based problem, e.g. a missing corner, or a half person, I use the very good and cheap Affinity Photo 2 for replacements.
Hi,
I am fond of digitalizing old and very old photographs, negatives and slides (including plates from the 19th century).
I use VueScan for an Epson (for wide negatives and plates) and a Reflecta 10 M for 24x36 and export in tiff. VueScan is great at inverting and restoring faded colours. DPL is efficient on these tiff files. I can even correct (if not too far from what I wish) white balance on old slides and colour negatives.
I often correct vigneting, which is common in old lenses, and it works well.
And with the distorsion tool I can improve some wide angle photos (such as the 24 mm side of a Canon 24-85).
Maybe I have been so used to working on older documents that I don’t see DPL’s limitations?