I use Firefox on Android as my main driver (former Mozilla eng) and I haven't had a crash, but have noticed sometimes videos don't load. On Chrome too sometimes, but usually the issue is with the lazy loading of images (Firefox lazy loading TBD https://bugzil.la/1542784).

I've been avoiding adding any JS, but interaction observers may be necessary since I haven't been happy with how any browsers handle 5 or so muted webm videos.