"New game plus - quests will have no rewards..."

[Callinon]

Lords of Verminion hasn’t seen any changes or updates since it was introduced. As for Eureka, they saw people leveling via the NM trains in Anemos and went out of their way to attempt to destroy that train in Pagos because we weren’t doing it as they intended (e.g., mob chaining).

Lords of Verminion hasn't seen any additions to it because it's:
A: A feature-complete system and
B: Nobody plays it.

It wasn't abandoned because people were using it for something unintended. It was abandoned because it was a dead-on-arrival system that served no purpose, wasn't fun to play, and offered no reward sufficient to mitigate the first two problems.

Well, this was a concern when PotD came out because of how much activity it was showing. And it persisted for a while on some of the more populated servers. It was enough that you could report players standing on the NPCs on their mounts and GMs would show up to knock them offline.

Still I don't think this would really be a thing in NG+. Like this theory really banks heavily on there being a LARGE number of players literally just spamming the same like six to ten quests over and over again, and while I'm sure there would be at least some players that did that, I doubt it'd be any kind of population worth worrying about. Eventually they'd move on or stop because what they'd be doing would be soul-crushingly boring.

My biggest concern is that the developers stop adding to this feature. We know that they plan to add in things like the new ARR and job quests down the line, as well as sidequest chains like Hildibrand, Alexander, and perhaps Coil and Deltascape. But if they see that people are mainly abusing this feature for experience and not story replayability, who’s to say that they won’t just stop adding to it/updating it. I don’t know if that would ever be the case, but I’d rather it not be.

If it's popular, they'll support it. If something about it is problematic, they'd fix it not abandon it.

Anything in an MMO that causes people to take solo avenues instead of group avenues can negatively impact the group experience. This is precisely why they made Trusts as inefficient as they are, for instance. There's still potentially reason enough for some people to use them (insta queues for instance), but there's still many others that won't due to the fact they cannot play as efficiently as a party of human players.

That's just a matter of tuning then. So the exp rewards offered from NG+ quests would have to be just a little bit worse than the same amount of time spent in group content. But then you just do math and figure out where that reward level is. PotD didn't cause everyone to abandon the duty finder even though it was numerically superior to doing dungeons. I'd prefer not to assume the sky is going to fall down if something like this is done.