I'm really liking IcoMoon premium's hosting option - it saves a ton of time/hassle when updating fonts. However, I've noticed that the latency is really high (375ms), which just wont fly for a production site. Entire sites can load in that time, and other font hosts (i.e. google fonts) typically have a latency of 50-100ms.
It seems odd that a global service like IcoMoon wouldn't use an edge-caching CDN. Have you thought of upgrading premium hosting from S3 to Cloudfront? That would likely solve the issue.
Thanks!
Wes