Samsung updated the community on their Samsung Tizen Smart TV 6.0 specifications somewhere in March 2021. Tizen 6.0 is the Tizen 2021 model.

To conclude, it seems they bumped their Chromium to v76, and added some extra documentation to their developer website at https://developer.samsung.com/smarttv/develop/specifications/general-specifications.html.

Chromium 76

Tizen 2021 is now using Chrome 76. The 2020 model was using Chrome 69. Nothing really noteworthy was added between 69 and 76 in Chrome related to video playback on Tizen, but feel free to read up through the links below.

Version	Release Date
76	July 30, 2019
75	June 4, 2019
74	April 24, 2019
73	March 12, 2019
72	January 29, 2019
71	December 4, 2018
70	October 18, 2018

Recommendations

Since our previous article on Tizen 5.5, Samsung did provide some recommendations w.r.t. ABR streaming. This article is located at https://developer.samsung.com/smarttv/develop/guides/multimedia/adaptive-streaming.html.

Basically, if you want to do 8K with MPEG-DASH and DRM, then use HEVC with the Main 10 6.1 profile with 1 I-frame per GOP. Don't use 60 fps. Use HDR+ instead of HLG and HDR10. Use CENC (CTR) for DRM, even though CBCS is supported as of Samsung 2019.

HLS is similar, but they recommend you to use 4 second chunks for live streaming instead of 2.

It's possible that some of these recommendations only apply when you use their native AVPlay API to playback video.