Is WP-Optimize compatible with Cloudflare

Yes! No special configuration is needed. Page cacheing on the WP site (that done by WP-Optimize) is independent of proxy cacheing (e.g. Cloudflare) – you can use both, or neither, and they will complement eachother and not interfere.

Just one thing to note – Cloudflare will strip out the special HTML comment at the bottom of the source of a page that is helpful to confirm that page cacheing is working, so, don’t be confused by that – it’s absence doesn’t indicate it’s not working.