Nice matrix of all HDHR tuner models this guy put up at Wikipedia
https://forum.silicondust.com/forum/viewtopic.php?p=378855#p378855
I think the first ATSC 3.0 tuner HDHR5-4K also had a DEV version (Connect 4K Development Edition)
Or was that just special firmware?
Special firmware. IIRC you can pay for the upgrade to get the dev firmware, which gives extra features, like full PLP capture and things like that.
Edit: Or maybe not. Their store lists the HDHR-4K-DEV as a separate model for purchase @ $299. If there was mention of purchasing a firmware upgrade separately, it has been removed from their sites.
i think the dev version is same board, different firmware, different case (or lack thereof). I admittedly haven't looked since the kickstarter, though.