Exactly. That's what zero-mot duellers have to do to play that way. But they need to keep their motivation down to zero constantly and not just once which means they have to do all things you mentioned all the time. So I don't see why it can be called a "cheat".
Perhaps you're speaking from experience, but if not, you should take what you hear from 0 mot duellers about the difficulty of that play style with a pinch of salt. I had a 0 mot dueller character for years and I can tell you that it's not a challenge in the slightest for the majority of people who take that route.
Sure, there are those high level 0 mots who duel only real targets and possess a lot of skill (certainly, many of the best duellers the game has seen were 0 mots), but the vast majority are whining, lazy, self-entitled, arrogant bullies who sit at level 30 or 50 and constantly KO njubs who have no chance to defend themselves. Then they feel good about it and have the hide to tell everyone else how much dedication it took them to reach 5k wins and 100 losses when really they spent two minutes and 10 energy a day duelling NPCs. Sounds harsh, but it's true.
Admittedly, it is much harder now that NPC and regular duel motivation is split (something that has flushed out many of those worker beating types. They showed us who they were in the forum after that update) but it's still not a huge task to keep your motivation at or close to 0 after a couple of days if you're active enough. It's a bit of work for a lot of benefit, which means 0 mots still can't complain about their lot in life, but at least it's closer to the way it should be. Regardless, I'd take that route over exp duelling any day, since it's the only sustainable way to duel.