Yes, Longmynd has been tested on an IQ file to decode the current HamTV system.
I've done an article in the latest CQ-TV out yesterday about the challenges of receiving it! Loads more info here viewtopic.php?t=4389
If you're looking for challenges to do with Open Tuner you might want to look at the MiniTiouner data record facility - very handy when seeing how well you are tracking the ISS!
All - please post anything more general about HamTV here viewtopic.php?f=2&t=8398