I’m curious to read about the rationale of using batched updates in Rum. I’ve seen reports that this kind of approach can lead to weird results when handling input elements etc. I’m not sure if this applies to Rum though.

it totally does

on the other hand, it saves a lot of re-renders when state changes in multiple places

It still does? I was looking for the bug reports and it seems like an IE11 specific behaviour that triggers this and happens even in React. Is it actually still a problem in day-to-day use?

I was digging around React internals and they seem to be implicitly batching inside event handlers — and they say they will increase batching in the future.