How to figure out which USB port goes to which USB controller?

You don’t enable autostart and you will have to reinstall Qubes.

So I repeat, don’t use your solution, better use unman’s one : “At end, you return to current state”, no dom0 reboots needed, and if ever dom0 needs a hard reset during the tests, the reboot would restore the pre-fail/normal state !

Off-topic: the doc I linked does not say “You don’t enable autostart and you will have to reinstall Qubes”, but last update was on Jul 9, 2021.
Please update the page if you are right ! I’d be happy to learn about that.
Also, my Qubes 4.1 boots nicely with this, and also if/when I set no qubes to autostart. This was very handy. Maybe my install is too old (no sys-gui, no sys-usb).

So I repeat, nothing is solution until the OP says that.
So if it’s better, why the OP isn’t used it.
So, why it is better - because of no reboots needed? Oh, G…
So I remind, this is NUC. If you have sys-usb, you have to enable autostart. Oh, G…
So, I’m curious, rethorically so to speak, why do you insist so?
So, I’m asking, why don’t you let the OP who needs help to decide?
So, my proposition, most easiest and straight forwarding is buried above because of you.
So, can you wait until OP writes something, please?

EDIT: apologize, I have overlooked qvm-start sys-usb at the end of the script. But you should anyway create separate sys-usb for each controller, because of better chances to avoid firmware poisoning of each of them when in one qube.

If I find solutions from @frank_sullivan and me are better, it’s because you can run safely those commands from a Live CD, without messing with your working Qubes install.
It may be of use to other readers : passing-through “unknown” devices can lead to disaster !
@SteveC so you’ve linked your ports to your controllers ?
And ignore @tempmail inappropriate response, he apologized to me via PM.

I have to apologize; I was dealing with two distinct issues and just spent the last week down a rabbithole related to the other one. (I haven’t quite come back out but I think I’m close.)

So I simply haven’t done anything about this yet.

It’s on my short to-do list.