Bare minimum, MM point scamming means that we utterly avoid negative consequences. It gives us time to sharpen our wits, and acquire leverage with our socially powerful party. We use that leverage to get into their perimeter, and then turn our scamming on the sect.
Best case scenario? We drive them off in defeat, and the Lich Lord owes us a debt, which we can use to scam them in turn.
Spend a month objective, and get a shot at rolling up every party involved with none being the wiser. Sounds good, right?
A month and .4 BP. It's decent but I feel that we might be able to do better.
Incorrect, if they were a happy brotherhood, they would combine powers.
Another Diagram Mage is a potential rival, who might plunder your vaults for knowledge, not an implicit friend.
Ah yes, which is why we know a spell from a Lich who is still alive. Trading happens, so fellow Diagramists aren't all bad. Further, even if they just come look at us, then they'll see the Ring and sincerely want to defer to us due to its effects.
Regardless, though, do you actually have a better search plan? One can take a sceptical position on anything but if you can't point to a better method then it's not very valuable.
Why? I'd expect the surviving Diagram magi to be enemies. They can't trust each other, as they can never know if one of them has been turned or wants to look their spells and resources. The only way they can survive like this is nigh perfect information security, otherwise one of them falling would have lead to the rest being rolled up long ago.
The locals have been living in fear of being brutally murdered by liches for generations, suppressing the population and keeping the place sparsely populated. You don't think the Sects wouldn't have a hard on for tracking down and brutally murdering the abominations against nature that keep causing them to lose face.
And Rihaku didn't say that those spells were Beyond enhanced. Just that they were spells known by the local liches, as a result, I conclude that they're regular spells.
Why does Rihaku mention trading so much if they're all enemies? Further, have you looked at the effects of our Ring? It makes Diagramists want to defer to us. Further note that the only Diagramist we've ever met taught us. They don't need nigh perfect information security, because Cultivators are low on utility effects and Diagramists are good at escaping, so Cultivators will usually go for the kill.
No, I don't, because these Sects are strong enough that they don't live in fear of Liches and greedy enough that they don't give a shit that mortals and weaker cultivators do.
There's more to spell quality than 'Beyond' and 'Not Beyond' as evidenced by Rihaku's descriptions of Baenlixnaire's time spells and by Baenlixnaire's descriptions of our self-developed spells. Just as those spells are highly refined, other spells can be unrefined. I think being relatively unrefined is what we should call regular, with spells like Haltsuphrect's Quickening and our self-developed spells being masterpieces and Beyond being a tier higher than that.