I just want to start this off by saying I'm in the vocal minority that actually likes Pagos and didn't much care for the NM train in anemos. Things like mindlessly blowing up mobs to hit 30 chains are something I enjoy doing and it's very much low stress casual content with the addition of bunny fates to break up that chain grinding with a little dangerous treasure hunting in the hopes for that rare expensive item. The NMs we have in Pagos I've mostly enjoyed and I think some of the mechanics like on holy cow/behemoth/Cassie/Luigi are cool. But with that said eureka can definitely be improved upon and here's a couple things I'd like to see in the future iterations.
Lesser Notorious Monsters - the mutation feature added in Pagos is pretty cool, the mobs transform and make u switch ur wheel in order to not get 1 shotted and they have a chance to drop lootchests for an added bonus, but I think they can add to it. LMNs would spawn rarely from killing a mutated mobs of the same type and would be on a 1 hour respawn. They'd show up like a rare fate that only people within distance can see(example being Ixion) and only have a 5min timer to incentive chaining. They'd give double the amount of exp ud get from a 30 chain to break people from their chains to go do and drop a low amount of crystals and loot boxes. Give them a little more hp and a extra mechanic or 2 and a added bonus if u give them a unique name.
Group Leve quests - Leves have all but been forgotten for combat jobs in ff14 and eureka is the perfect place to bring it back. Give people a set amount of eurekan Leve points per week and a quest giver with various things like go here and kill these mobs or escort this person there for example and everyone in ur party gets rewarded with exp/crystals/lootboxes. These group Leve quests break up the endless grind of chains but still keep the focus on small group play.
Even more variations in agro - I thought the agro detection in anemos was lame where everything was deaf and would only attack if u were literally right in front of their face, with Pagos some variations were thrown in to make it more interesting, but I'd like to see this taken further in future installments.
Roaming Hunts - roaming Hunts would be about 4-6 monsters on a 2 hour respawn that grant roughly a medium sized NM fate worth of exp and some crystals/loot boxes and spawn like the regular S ranks we have on the main land, by doing so strange and random thing. The only real difference is these guys won't just sit in the location they spawn so if you see these guys spawn next to ur camp u better shout for some end game players to get rid of this guy fast. There would be no fate indicator for these hunts like regular hunts.
(Edited in) Party level sync - some kind of system that let's the player, if they so choose, to sync down to one lvl above whoever the lowest lvl in the party is so you can play with whoever you'd like regardless of how dedicated you are to eureka as a whole.
(Edited in) Defend the Fort - Eureka is like a wild frontier and it's odd to me at least that the camp is always safe. Starting on the first hour of an instance and proceeding every 3 hours, with warnings 30,15,10, and 5 minutes beforehand, a massive assault on the camp will commence with bonus exp per mob killed with pre mutated or adapted mobs apart of the fray with a final beefed up version of a random NM to finish the assault. NPC defenders will spawn in like some Fates you'll see just to draw agro so players aren't swarmed off the bat but the NPCs won't be able to hold on for very long and this would very much be a instance wide event with large amounts of exp/crystals/lootboxes to be had.
Tldr: basically I want things to break up the chain grinding and offer other ways to get exp/your relic weapons while still having the focus be on your party and not devolve into a NM train
If anyone has any thoughts or ideas they want to share I'd love to see them.