Sounds awesome, actually. In encounters like this the boss is also a threat outside of casting "Big Damage AoE Attack" or "This starts a dance of mechanics". Right now, most bosses reposition themselves into the center of a square or circle arena for mechanics, and all of their damage is pretty much predetermined. In most cases currently, the least important thing in an encounter is the boss itself. You dont necessarily have to worry where the boss is positioned, or you dont have to worry about their autoattacks.
Maybe thats not what the game should be about anymore, but sudden spikes of damage need to be reacted to which will always keep healers on their toes, especially with crits as that isnt something that can be put onto a timeline.
Not that this has to deal with Healers, but I really hate how 90% of boss arenas as circles and squares. Caduceus' arena is so unique as you need to worry about if you can easily move up and down on sections of the arena, they should do more stuff like that. The shape of the arena can influence an encounter so much, but its almost always circles and squares, I assume because its easier to plan out a fight.
And isnt that a whole thing too? Making things easier for the devs? No trash in raids cause its easier for the devs just to make the arena. 12 bosses in Pandemonium, and we only see 7 places in it (since I wouldnt count P3, P9-12). An entire giant facility full of horrid creatures and abominations created by the ancients boiled down to 7 rooms completely divorced from each other, and all circles and squares aside from P2(sorta) and P10(though the main area is also just a square).
SCH dps kit simplified because it would be easier to balance as a healer. AST cards boiled down to boring damage up cards because its easier to balance(lol) the utility of the old cards. Cross-Class stuff simplified into selectable Role-Actions and then removed aside from what was deemed mandatory and packaged into your role as your level up. Healers and tanks homogenized. Enmity management mostly removed (aside from tanks swapping). And of course, the tons of utility that wasnt just "Damage Up" or "Reduce Damage".
Sorry, kinda just a little rant that kinda ties in a bit to issues surrounding healers, but mostly just the game in general.