In the end the worst thing is how repetitive lab quickly become, since the bestiary always is the same, going back from T10 to 6 just feel like a plain downgrade, and I understand the feeling of labour that can come from grinding back to simply get to a place you gain xp again. I know since it's that very feeling that made me not farm to 150 this season, even if I could. And it was my first time grinding labs, I can't even imagine for someone that try multiple seasons.
It's not like T6 have something that 10 have not or something, it's just everything less, and no xp after some point. Honestly I don't think it's as simple as giving the place more rewards, it also need a pretty big rework.
Another thing I wanna mention if we talk about endgame in general is the endgame bosses. Samael is amazing and my favorite fight of the game. Except it's very stupid Taha requirement that pretty much says "hey no ssf allowed" (if it were me I'd put a "taha+ghal+qor" that you have to use only once to upgrade the stone, then every attempt only eat sigs), the fight itself is nice and reward playing well. Compared to that, Deimoss is a very boring dps check, with potential obnixious totem debuffs, the "your screen freeze" attack, err I mean the meteors, and the random elite spawn that decide entierely how hard to fight will be. Nithogur is even worse, it's literally a gear and build check, you either die or have the dps (and solitudes/farnhams) and right clic the boss to death. There isn't a single engaging or exciting thing about it.
And I think that's where the line between nice balance and obnixious balance is. Samael represent that line ; It's a boss that can be done on a very scuffed set up with a proper plan and gameplay. But farming him consistently require a more impressive gear, more umos, better preparation etc. It's a line that players don't have to cross, but it give incentive to do so, and many will, especially if the reward is worth.
But now, any tentative to do content harder than that will simply not end up working properly due to how the characters scales currently. Because theses content end up balanced the way they are because they're made around all the op things that can clear them. The Solitude, Farnhams, Banish abuses, some specifics builds, etc. And anyone that don't use them will have a bad time. And no, making a very specific list of skill that abuse thoses op mechanics the best completly unusable by giving deimoss/phob/new boss some avoid when using them isn't the solution, you're just asking for a next skill to show up without addressing the core issue.
In the end there would be so many thing to change, but honestly I don't really know what to do that could help. And anyway, to me Deimoss and the new boss are such a complete mess of a fight that they need a complete change, and that can't be helped by throwing around suggestions. Labs isn't as bad, and have some nice ideas and mobs, I believe Phoboss to be real nice for exemple. I'm not really for unlocking him from a totem, to me the best part of labs is when you see his icon showing up, and you have to prepare for him, find his position and all that. But of course entrance Phoboss, surprise phoboss
, or phoboss + friends (when a navigator come at the same time and follow you and you can't escape because of phob arena, haha), thoses feel bad. But they feel bad because they make us grind stones again, and we're back to problem #1.
Adding randomness to things isn't the problem, if anything it add some fun and variety. The problem come when there's a grind to simply attempt said randomness. Samael cold worms aren't bad mechanically, but they feel bad because we used a taha just to enter the arena. That's the same here with labs or Deimoss, but much worse.
Gotta say, the T6 drops that was recently added was a really nice touch, without it I'd have dropped labs 10 time earlier for sure.