I don't mind if I can't pull the roots. If I can pull the top half out, that's 3/4 of the organic material removed.
My bigger concern is whether or not the plant is likely to grow back again. Does the herbicide need time to get down into the root system and kill the plant? In which case I can give it time (though it's actually been 4 days now...but good to know for future reference). Or will it just kill off the surface portions anyway, in which case, I should have simply done a manual removal and simply expect them back a couple times per year.
This is really the only aquatic vegetation that has been somewhat aggressive. At first it was one or two specific spots in the pond, then this year, it took hold all the way around. I didn't remove any last year until after seeds were established, so it's largely my own fault. FA and other algae have been easy to ward off, and I'm keeping an eye on cattails, but they've haven't exploded or anything.
