Some like a endless gamemode where there is waves an after each wave more enemies come and after every ten waves there is a boss and the more waves that you complete the more meseta and xp you get and after a certain amount of waves it asks the players if they want to to go back to the gateway ship

So you're suggesting something similar to Mining Base & Buster Quests, w/out the towers, but unending. & for breaks like Endless Quests have a teleporter to a shop for restocking & an activate teleporter in that space to return to the combat zone?

Another thought would be when do you collect your rewards, how will that be determined?

@Church10129 It could be handled like how Warframe has their Endless Missions (Defense, Survival, Excavation, and Interception if I recall) where every five waves/five minutes players can pick up their rewards and get the option to stay or leave.

I feel that for the case of Phantasy Star Online 2 it is very late for this but I would see it as potentially a smoother run than the current Mining Base quests considering that Endless Quests are similar in structure and gameplay to Warframe's Sanctuary Onslaught (though in Warframe it is seamlessly teleporting from cell to cell with randomized enemies for pure action where in Phantasy Star Online 2 you don't exactly get very good rewards from this and instead serves as a test of the player's knowledge and skill in its hardest content).

@VanillaLucia Sanctuary onslaught isn't much for action with a Saryn deleting the map with the press of a button(or two). At least you can't do that in PSO2.