There is an existing bug report thread:
https://www.eevblog.com/forum/testgear/rigol-dho800900-oscilloscope-bug-reports-firmware/It has been littered with side discussions etc., so I understand the desire to have a "clean", bug reports only, thread. But I don't think the "no questions and discussions please!" approach is going to work. There will be unclear reports, false reports (operator error) etc., multiple people may have comments/questions/clarifications, and sorting all that out by PM will be a nightmare.
If you want to put in the effort and keep an organized bug list, I would prefer the following: Allow discussions in the thread, but regularly update the first post to make it a concise, up-to-date list of known bugs. (And, ideally, bugs fixed in the various firmware releases -- Rigol's release notes are known to be incomplete.) Still a significant effort and commitment, but better than managing a very busy PM inbox, I think...
Oh, and I would not bank on Rigol reading this thread, or even acting upon it. The only known instance where they responded to an EEVblog bug report was nine years ago, and that was in response to a very visible EEVblog
video on PLL jitter.