I think after a week or two the novelty of new dynamis will wear off and it will go back to being mostly ignored.

However i still think your idea of once a day/run NM limit would help alleviate some concerns with NM monopolization

I'm not sure how they would implement it tho

I certainly hope its nothing like walk of echoes.

Maybe something similar to the fov elite regimes.. where you have to be in the party when the NM is spawned to help fight the NM... and you can't join halfway.

That way the KI you received when you entered that dynamis run would be consumed and they could track whether or not you have killed the zone boss that day.