Unfortunately the developer is MIA, so the few bugs in the beta aren't going to be fixed anything soon. The most important feature of the beta is wildcard support, so you don't need to add every cloudfront sub-domain manually.
I did not like the beta interface for RequestPolicy and I hacked in support for using regex matching for whitelist entries so CDN domains like CloudFront work correctly.
1) I have absolutely no intentions of continuing any work on my hack. The changes I made meet my needs. Feel free to fork if you need additional features.
2) I don't pretend to be an elite javascript developer. I have no idea if my hacks are considered idiomatic javascript or not. I also make no promises that running my hacked version of this extension won't upload all your private data to a server in Russia or cause other problems like having your hard drive explode in a ball of fire.
https://www.requestpolicy.com/1.0.html