@v4 I am unaware of the current state of CF's caching mechanism. It may very well work fine with NodeBB, but when I tested (1.5 years ago!!) it did not work well.
Namely, CF's new Rocket Loader was minifying our already minified files, and possibly serving them out of order. If you investigate the source of a NodeBB page, you'll see certain scripts that are not bundled into the minified js file. CF modified the page html to load their own cached js, possibly loaded scripts out of order, and things just didn't load properly.
CF also doesn't proxy websockets correctly (except for the most plan, but this may change in the future, hopefully).