But why though? At my desktop workstation both of my monitors are exactly the same brand and model (and sequential serial numbers, if I have a choice) and that's exactly what I would want regardless of my OS.
Why would anyone not prefer this over a mixed set up? The only reason I see to use a mixed set up is if you're forced to use a laptop. Personally I don't optimize for working in meetings and planes though and my life is just simple and straightforward. I keep just 1 cheapo laptop around for that stuff.
With that said, XFCE handles mixed DPI/scaling just fine for me.