Tanks get to set the pace.

If you want to control the pace, you may politely submit your request to the tank for consideration or queue as tank yourself.

There is a subset of toxic healers in this game, who seem to want the entire run centered around them at all times.

Tank doesn't run at the healers custom preferred pace (which we can't know btw) and the healer throws a fit, but if the tank asks a healer to DPS instead of idle "we don't pay their sub"

Tank doesn't use convalescence, it's the end of the world. Healer forgets largesse, it's the tank's fault for pulling to much.

To toxic healers: we don't know what pace that you specifically want and not every healer want what you want. Feel free to ask for a particular pace, but if you feel it is appropriate to ask a tank to change playstyle, make sure you are also open to requests to change yours.