With a hacked switch? No. Lan play doesn't use offline AND online capabilities at the same time.
If you're worried about getting a ban, if you're using your Sysnand so long as you're not pirating, cheating or doing anything that will flag your console as hacked then you should be fine. If you aren't, then there's a good custom design pattern injector that you can use in lieu of the design portal, so your console doesn't have to connect to nintendo servers.
edit: If you have bought a pre-hacked switch then don't use Sysnand at all. You don't know what the previous owner has done on the console, so better safe than sorr
With a hacked switch? No. Lan play doesn't use offline AND online capabilities at the same time.
If you're worried about getting a ban, if you're using your Sysnand so long as you're not pirating, cheating or doing anything that will flag your console as hacked then you should be fine. If you aren't, then there's a good custom design pattern injector that you can use in lieu of the design portal, so your console doesn't have to connect to nintendo servers.
edit: If you have bought a pre-hacked switch then don't use Sysnand at all. You don't know what the previous owner has done on the console, so better safe than sorry.