So i was thinking in some things that could really help Oz in it's current state without making drastic changes.
First i tought on a new pill slot that you would put a pill that can save what floor you were in case you dc, it would be used and restart the floor you dced, trowing you back at it like you just entered, and having the time you had when you dced, would be able to hold one dc, surely would be nice for anyone.
Other would be to low down some of the RNG that oz have, some floors can take a lot of time because you got bad lucky, for a place that take a lot of skill to master, getting a bad time just because of that can be really frustrating, i tought they could make some floors quicker if you have more pills slots/some condition(ex: at 29f the max required crystals would be 6 if you have 4 slots and 5 crystals if you have 5 slots), like how 2f could simply remove the 1 cards that end up just screwing over anyone(also in 9f they can make the last plataforms visible what is the correct one, more pills=more visible up to 3).
Other thing would be to incentivate party play, something that can be for any event/quest killing would be a higher count for every mob you kill if you are in a party with 2 or more, so every mob you kill count as 2 instead of 1, so people would go together more often(only downside is how people wouldn't go solo since it's slower).
I also tought how you could enter with all the party at once in some floors and everybody clear at once, making moving with a party more easy(i saw in a private server people passing trought stages and beying pushed together like a party quest).
They could also change the Oz rings to make em tradeable with platinum karma/normal karma once equiped, they are untrad once you equip and if you want to sell later make it really frustrating, besides how they could change some rings to be better, some of em are bugged as well(making it annoying how potentialy good rings are beying wasted).
And one thing that came to my mind is that Dorothy says she would come back, so what if Oz had floors 51~~100? Giving better medals(like 20att/matt), more rewards, and you could also start directely from 51 floor.
Then there could be a chaos Dorothy(10xnormal Dorothy HP) too, floors with mirrored JQ's you previews faced, and also more mobs to monsters collection, since it's impossible to finish Oz set and the Near Victoria as well(making the orange beetle acessible?).
A revamp it's not that required, since Oz already cover all the stuff you can do in the game, so what else could do to fill 50floors? Besides that in KMS is more popular so i don't know if they would enjoy more floors to make the content fresh again, and more rewarding as well(maybe it's already too hard?).
Aparentaly the impossible monster to collect in oz atm:
