The only DPS I've ever absolutely had to do was helping push the phase shift after adds die, Potent Poison Potions during the first days of being on the fringe with gear as a team, and remembering to pop Fluid Aura whenever it's off cooldown (and whenever mechanics don't have positioning as a worry) on Imdugud himself. I haven't tested and won't test if the sons and daughters can be pushed by it because fucking up positions sucks.
For the most part T10 can be covered almost purely by the WHM of the group. My group's SCH's speedier mitigation to deal with Prey, emergency Lustrates, and Wild Charge recoveries are typically the only heals required. That's a LOT of downtime to let dps instead.