I just spent the last hour trying to find a way to bypass HDR on Disney Plus to watch The Mandalorian. First tried my Fire TV...there is no way to turn off HDR on Fire TV. Next, I tried an old Android TV box...it allows you to do HDR to SDR, but no way to disable HDR metadata from Disney, so that doesn't work either. Tried downloading the DIsney Plus app in the Wndows Store, although it says requires X Box OR Windows 10 PC, the app only works on X Box...so that didn't work either. I then tried my Windows 7 PC watching in Chrome...yay, it works, SDR, but no DD+ audio. But wait, there is a Chromecast button in the corner, pressed that, sent to my Sony X900F TV, yay ya yay, proper SDR with proper DD+ with proper 24Hz playback.
Why all the trouble to see this in SDR? My SDR calibrated picture has a black level of 0.028cd/m with 100nit brightness. The black level on my HDR calibration is 0.16cd/m with peak 820nit available in HDR10 or DV. Watching 200nit peak brightness content with a 0.16cd/m blakc level is HORRIBLE. Maybe if you have an OLED it would look better, but for an LCD TV, it's garbage. You can do the math on contrast levels for the above specs I listed.