Just installed the latest update and my Rock64 is correctly flagging HLG HDR to my Sony UHD TV.
Unlike other bits of kit (Amazon Fire TV Stick 4K and Roku Streaming Sick Plus) that needed an HD Fury Vertex in the way to add an HLG Support Flag via EDID (not sure why - an EDID dump of my UHD TV EDID shows it is flagging both PQ and HLG EOTF support) - the Rock64 works fine connected direct.
Unfortunately I can't get MPEG DASH streaming to work to test it with the live iPlayer test stream here :