btw I've been meaning to write a blog post on this...

In building custom-elements-everywhere, I've seen issues in various libraries around mixed case events. I'm increasingly of the opinion that, as a best practice, event names should just be all one word, all lowercase. That's how the platform handles things today: beforeunload, pointerdown, etc. and I've only found a few exceptions (which seem like anachronisms) e.g. DOMContentLoaded.

By sticking to all lowercase, all one-word, you free up the libraries from each needing to invent their own heuristic to grok what event name you were actually trying to use.