After playing around with Fuel Streams a bit, I would like to offer the following suggestion.
WebCore does a wonderful job giving people tools to create simple and complex automations for their home. Fuel Streams are cute but ultimately seem to come short for advanced users; putting together a scalable, reliable (and hosted) TSB (TSDB) and accompanying graph engine and customizable portal is a lot of work. In my opinion that’s not what the developers should focus on.
Leveraging the simple Web Request action, I was able to, after having built a proxy in node.js, push metrics to a Graphite server (there are hosted Graphite as well as other TSDB). I was able to also push annotations (presence and other events) to my system.
I am happy to guide others to achieve the same and share my proxy code once I clean it up.