Good healers are always going to have some down time. Stop ignoring that part of our gameplay, acknowledge that it exists, and give us something to do when we have it.

This. Here. Is the issue. Give all the healers the robust dps kits to use if they have downtime. If that particular player doesn't have downtime then they can focus on healing. If the green dps is necessary to complete the content then that player is simply not skilled enough and that's ok. I'm not a professional gamer. I don't white to the league of legend devs that so and so champion is too hard. No, it's just beyond my skill level and i'll play something else. That's fine. We all can't play in the NFL. Some people are just better. Giving all the healers a robust dps kit or buffing kit or debuffing kit or mix of all three can accomplish the same thing.

This way healers who feel bored have something to do to contribute and the healers who for whatever reason can't keep up with the healing and dps don't have to. Right?