Before I re-invent the wheel figured I ask if anyone knows of a public utility or open source to do this already.
If you don't understand what I am talking about, go to any public activity in strava and put /streams after the url
Basically a raw dump of much of the activity record by record but in their own format
I found a gpx tool but FIT would be way more compact and precise, converting to native field global message ids etc.