It would be nice if there was a setting to ignore the childish community flagging nonsense. I do not like to have to click to read posts, especially when they are disappointingly tame.
On topic, the problem as I see it is more playerbase than roles. It is too small to sustain ten dungeon levels, many of which are redundant anyway. E10 is nearly unused, as is story. E1 is so simple it may as well be story, e2-4 are nice for newbies, but are effectively the same when it boils down to it. The higher E levels are not particularly different from each other, its just scaling.
Of course that scaling is done very poorly and draws attention to balance issues between the roles and incoming damage, aggro handling, and so forth. The ridiculously badly balanced HR fights are another matter too. To truly compress the tiers, these things need to be dealt with first, or it just won’t work very well.
I think, though, once that is sorted, a potential solution may be to simplify the fights a little bit, and then put in a timer on them all. Say they combine E5/6/7 into one. It feels like your regular E5 fight, but if you beat the boss in X seconds you get E7 rewards. In X+Y you get E6 rewards. If longer than that just E5.
This would generally benefit higher level people running “lower” level queues as they would speed up their time spent and their DPS would help get better rewards for everyone, while it encourages lower levels to improve gear and tactics, and not just die and be carried.
Of course, given how badly they got the Machine Tyrant timer, I’m not confident this is a good idea, and some fights a timer is nearly irrelevant due to the hurry up and wait mechanics (DW5, Pol 6), and it also would be a problem when people died mid fight, pretty much ensuring you drop out of the top tier of rewards.