With respect to components installed with $ idom install or idom.install() there's definitely some limitations that, unfortunately, I haven't really had the time to document yet. In short, all component props have to be JSON serializable, so that's a problem if you need to assign a JS object to a prop. This is a common pattern in Material UI so it's come up a number of times in that context.

That probably won't change though because there is an interface for integrating your own custom components in JS and distributing them as a Python package. However, I have plans to reconsider that soon so I've been hesitant to suggest people use it.