what about dl updates from ninty servers on emunand?
If you have Nintendo servers blocked on your emuNAND and want to use MIG Switch on that emuNAND, you can install the updates the usual way via your favorite title installer (Tinwoo, DBI, Tinfoil, Goldleaf, etc.)
Anyway, if you have emunand, you already have a modded console, so why bother with a MIG at all?
I hardly see a point as well, as you can opt out for a bigger SD card instead of using two smaller ones, one for the Switch and the other one for the MIG Switch. Plus, cycling through the games on MIG Switch is a bit of a chore, so I'm not really sure if it's even worth the effort.
MIG Switch and alike provide a decent way to backup your own cartridges so that you don't have to carry all your expensive games around with you. In this case, you're unlikely to get banned if you make proper complete dumps of your games. Another good case, as proven by TheStonedModder himself, is sharing games between a close group of friends, though it might be a bit tricky as we don't know how Nintendo will deal with the shared certificates in the future. So far, he didn't get banned and that's a good thing.
Using MIG Switch for pirated content might be tempting for some people out there due to the fact that you don't have to do any hardware modifications to the console itself, despite all the limitations of the MIG Switch, but to me it's just not worth getting your Switch banned.
If you have a banned patched Switch, don't want to install a modchip and have a modded Switch as well (for installing updates on a banned Switch), using MIG Switch for games on that system might be a "decent" use case, despite the limitations, if the end goal for you is just being able to play a couple of games. Keep in mind that the more games you have on your MIG Switch, the more annyoing will be to cycle through the games it, especially if you have a v1 MIG Switch (one without a button).