There shouldn’t be a conflict, just unnecessary doubling of features. If you’re going to use Cloudflare APO, you might as well make your site lighter by removing other optimisation plugins.
Having said that, Cloudflare minifies each resource separately, so it may be better to use Autoptimize for page optimisation and disable those features on Cloudflare.
Also, APO covers the page caching feature of WP Rocket, but not things like object caching, so if you use those, maybe just disable page caching.
Ultimately, it’ll be good to test various options and decide based on actual results directly from your site.
One more thing to consider is that turning on APO eliminates most of the visits to the origin server, so if you’re relying on visits to trigger WP Cron for running background jobs, you might need to set up alternative ways to trigger it.