May I ask why? The dungeons are not exactly hard, and are designed, post HW, to be doable by pulling 2 groups of mobs at a time. There's no reason a healer should be struggling to keep you alive, and you have your mitigations to help stay alive.
I'd also like to know why you always ignore me and others who ask you to pull more. I always politely suggest you pull more than one mob, but never once has such a tank ever responded and just keeps pulling one mob at a time. It's not just a few instances, it's EVERY instance of a tank who only pulls one mob. You guys never respond and just keep one-mob pulling.
There is absolutely zero reason to pull one group at a time. It's extremely boring, takes away what slight challenge I may have had as the healer (forcing me to just dps basically because one mob isn't enough to really require healing generally), it's slow, makes the dungeon take twice as long. Why do you insist on tanking this way?