Autoptimize is compatible with all themes & plugins, just not always out of the box pulloverschaf, in which case you can configure AO to fix any problem that might present itself as per the FAQ ??
Specifically for Avada; as this is a premium theme I can’t simply download & test it. I’ll be happy to assist with any troubleshooting if you’d encounter problems as I did for others.
have fun,
frank