Not yet. It’s high on my list of “things I really want to know the answer to” but low on my list of “I’m going to spend time on this now.”
I did start by looking at a list of processes running under each account, but that’s a very long list and I don’t know how to tell which processes running under the regular account may be having an effect on the new one. The scanning works when my regular account remains logged in, so it’s not as simple as “something starts” on that account.
I’ve never used multiple accounts on a Mac before (aside from basic troubleshooting for Apple) so am not sure what to expect.
I have now scanned 204 slides and over 50 negatives without a single issue, so it is most certainly working. I just log into the separate user account and I’m golden. Particularly when scanning 8 negatives with 2 passes (one infrared for dust removal), it’s long enough to just walk away and do something else for a while, rather than do other things on the Mac at the same time. The latter being hindered by it not being my usual user account.