You may have to use several codecs for each type of format. Uncompressed 8-bit is way too much and you’re wasting hd space.
I did this couple years ago and the biggest issue with legacy analog VHS and UMatic 3/4″ SP is the TBC. Your deck must have it or else when you get to a trouble part, the capture device will give you an error. Even with the TBC, the signal sometimes will over the legal limit and capture would stop on its own regardless. It’s a pain in the neck. You may have to baby sit it.
For Hi-8 and miniDV: I’d get a consumer digital 8 camcorder w/ firewire and capture it that way. Cleanest possible quality because it performs chroma noise reduction on the higher end model. Huge improvements. MiniDV is pretty much everywhere back during the 2000s and any consumer camcorder or deck should do. Not sure if you’ll gain any benefit by going out to analog and go to SDI. For those who’s a digital purist, it’s best to keep in the miniDV tapes in Firewire DV25 domain because you’re extracting that miniDV bit for bit and not going to further compress and encode cycles. Once you take that miniDV signal and go to SDI, it’s not bit for bit anymore (except for STSDI deck to deck dubbing).
I used the Decklink Studio with analog inputs. There you can select the codec of choice. Uncompressed is overkilled. Pro Res 422 is plenty. Even DV25 is overkill for VHS. DV25 should be PC & Mac cross platform. Don’t use DV25 for analog component Beta SP. ProRes 422 is the ideal codec for any Betacam SP source.