Why IS the performance so poor?

I've moved to using this component instead of [the other one](https://github.com/buildo/react-autosize-textarea), as the other inexplicably stops all transitions from CSSTransitionGroup and the like.

As I've seen reported on here already, when there's a lot of components in use, it's real janky and lags a fair bit - far more than I'd expect from simply doing some calculations involving font sizes and line-heights and whatnot.

I'm not here to complain, but as I've seen a mention of adding an ID increases performance for some reason, are there any other undocumented things we should know about that could smoothen things out a little?