I would say at least from my personal experience that chain pulling is the standard. That being said how a chain pull is done and how difficult or easy it is to get through it isn't standardised because different players have different levels of skill and experience, have different habits, sometimes people make mistakes and not everyone has the exact same gear.

There are so many variables that can make the same content feel totally different with different groups. Certainly as a healer I experience this a lot. I can very quickly tell if the tank knows what they're doing and is confident about it. The only time I feel legitimate consistency from repeated trips to the same dungeon are when I'm doing the content with my friends.

And no I'm not allergic to single pull packs. I prefer chain pulls unless the tank clearly cannot handle it and/or if the dps is just too low to make it a logical decision. If a tank doesn't chain pull I simply say "you can pull more if you like" and if they don't it's very whatever for me. I'd rather take things slower than place stress on a person whose gaming background I'm completely unaware of. I don't know if a random person hasn't tanked in ages, has only recently begun to do it, etc.