In an excellent Lanner Chronicle blog post from 10/20/2020, a quote from Richard James (aka Aphex Twin) from the artist's Soundcloud account is archived:

“here is a download gift / sneak tease for the fans, to show the kind of quality I’m extracting from my old cassettes using mega high quality cassette decks. Because I’ve customised the decks with vari-speed, I get to choose what speed I encode them at, I’ve done a few different speeds for my fave ones and it’s usually just what I think sounds good at the time or just different to what I’m used to. This one is from a That’s cassette labelled copy III , i used a lot of the VX90 tapes in that period of my life. It is the 12th track on side a. Even though I used to write COPY *.number, they were actually the original masters. Think was one of the first tracks that a small section with intentional microtuning, [harmonic series sec] .Encoded with customised Nakamichi CR7e cassette deck."

While the recording medium may seem like a trivial detail, it obviously does make a sonic difference in the case of analog tape, and was clearly a meaningful artistic decision for the Artist then and now.