1) If you do Slack, then I recommend you join the #openfeature channel on the CNCF Slack. The inviter is here: https://communityinviter.com/apps/cloud-native/cncf

2) The downside of rolling it out based on host is that you could refresh your page, hit a different host, and see the UI bouncing back and forth between versions. As long as you always plan to roll things to 100%, this is the perfect use case for a feature flag.