This is actually pretty common. The real current industry standard is actually “no automation”, which ISBoxer and a few other similar programs comply with for just this reason. That’s also why Glider got banned and ISBoxer did not, because Glider automated the game and played itself.
So what does this leave us with? That would mean we do allow multipe accounts without a device ID block while taking an extreme stance against against cases where somebody uses 2 or more accounts at the same time such that they provide a direct play advantage to each other (i.e. running the same dungeon, going on a PvP Albion Online Silver spree, using a second account for scouting ahead of your group with your main account being part of the group, etc). This definition of course would cover all instances of multiboxing. Penalty for this would be a straight out ban.
This is still pretty slippery territory when you get down to it because what defines a “direct play advantage” can be different to everyone. For example take the husband/wife combo. One of our couples the guy plays a healer and the wife plays cursed staff. If they are dungeoning together, is that going to be a “direct play advantage” scenario since they are doing content together? If they’re gathering together is that a direct play advantage? What if the husband uses the account to transfer or hold goods for his other account? There will always be an excuse, always be an explanation, and always create a grey territory where it’s impossible to tell.