So odd to list a timeline but not enough detail to work out what happened.

Such is life with CVEs, unfortunately. While there are some great central repositories of information there is often very little in the way of consistent information on the disclosure process itself.

It's pretty clear to work out what happened from the timeline listed: RIGOL didn’t do shit.

The style the author chose to list the timeline is IMHO the most faithful, honest, and polite way of communicating it without adding wrong or legally problematic reasoning to the situation, from their perspective.

Nah, "no response received from RIGOL" if that's the case is faithful, honest and polite.

This is RIGOL we are talking about. In a year, they will release a firmware that solves the RCE but opens two more and also breaks cursors (or some other very basic thing). A year after that, they will release a second firmware that fixes the cursors but breaks the calibration and still has the two new RCEs.

In my experience this is most firmware vendors

I actually reported the same pair of bugs to them 2021-03-01, so I don't think they're interested in fixing it...