I am going to digitize lots of miniDV tapes in hopes of keeping these older recordings accessible for the future when equipment to play a miniDV tape gets really scarce.
My question is, for future compatibility (crystal balls out y'all) do you think I should transcode the footage to APR 422 files (I was thinking LT) on injest, guessing that 10 or 20 years from now that codec will be more useful than if I just digitize the footage directly as standard def NTSC file?
Since miniDV uses the DV codec over firewire as its standard, i would save these tapes as DV files. That way you have a bit for bit copy of the original, with matching timecode. Anything else, including ProRes, will be a recompression.
If you're going to use ProRes, i would go with ProRes 422 or ProRes HQ. Since they're standard def, they will be way smaller than HD ProRes HQ anyway.
I would then save these DV files on LTO if possible.
It's hard to say what the standard will be 10-20 years from now. There's no guaranteed codec, especially when you start talking about licensing issues. But if you gave me a 15 year old DV file, I could still use that today. The other formats from 15 years ago would be harder to use or decode. For my extremely paranoid clients, we save masters as DPX or TIFF frames.