And I'd say it wouldn't be unfair to have it effect crimson roots, given that you would need to put a lot of perks into alchemy and be pretty high up in the skill to do that. Wouldn't be the first or only time high skills resulted in a much faster/easier quest...
That's true, I see your point.
And are you saying you go back to Blackreach to get more crimson?
While doing the MQ I got a couple from the Lab and near the entrance to Blackreach. When I went back much later, I came out with 44 from the Roots quest and the ones I took earlier did not respawn.
Did you stop at 30 and then go back for more? I'm a little confused by this, assuming "a cave" refers to Blackreach:
"I did the root quest....but now I use the crimson nirnroot for regular alchemy and running all over a cave to pluck one at a time does actually get pretty annoying. "