So I was watching a couple things on my Plex server while testing out the refresh rates. I turned on Back to the Future to test out the 24p. I went to see what the refresh of the tv was set to and it was at 60p, not 24p. To this I have to say I need to see an update to this because the main reason to me picking up this dongle was to get rid of needing an xbox in my home theater room. Now that I found this info out, I will have to switch back to my xbox until an update has been issued. In the settings currently there is an option to match contents hdr/dolby vision/sdr but not the refresh of the show.
It’s a Google problem, they simply are too lazy to implement refresh switching even with their very own Movie and TV shows video player Apps.
The best you can do is use a TV that has Judder free 24p:
https://www.rtings.com/tv/tests/motion/24p
But that is no good for 25/50fps video content.
The Google dongle is focussed on video Streaming where the mainstream masses care very little for nice smooth video playback.
Apple are the ones that seem to be aware that the world needs Refresh Switching support and their Apple TV HD/4K is the best at it vs the competition.