Nice review as always. Strange some folks really took offense at some comments, I guess PSU is a popular item.
I think the Rigol PSU interface is unique and well designed, and between 3 similar linear programmable supplies in this price range, $400: Rigol, Atten and Siglent, Rigol is a better bet long term; support and firmware updates and likely hardware build quality; so its bang for buck except for the 2V switch on issue; it could be fixable via firmware. The rotary dial layout is strange, but not a deal breaker.
That said, they are fairly close to each other with the new Siglent looking fairly competitive, and a lot simpler in layout.
The Atten is sold as Tenma house brand in the USA:
The interface has to be spotless because its all the operator has to go on and if its not idiot proof, the operator can make errors setting one or all the supplies; the Atten glitches doesn't build confidence that the output will behave later on, I'd still be checking it manually with a DMM. The risk of blowing an expensive IC or test board is one reason I still prefer, for lab work, all manual switches and no programmability.
If I were to buy a programmable supply I'd prefer a continuous output monitor like Shariar showed in the more costly Rigol model, so I can track issues. Getting a graph over time, as the 34461a DMM shows, is great timesaver particularly if a glitch occurs beyond the capacity of the PSU to regulate:
That said, I still prefer 3 single output supplies for redundancy and reliability; if one output dies, I still have the other two whereas a 3 in 1, the whole supply is taken out for repair should one supply go even if the other 2 are working, or worse a single output failure could take out all outputs.