I have a Roku Ultra LT on a 1080i HD TV.
Will the Roku downgrade/transcode 4k/4k HDR files so that they are watchable on my 1080i TV?
I don't have an Ultra LT, but I do have a 2020 Ultra. I tried to play a 4k video with the Ultra connected to my 1080p TV and I got a copy protection error. I could briefly hear the audio. No Roku has ever supported 1080i in the past and I don't believe that's changed, so you'd have to use 720p. I just got an onn 4k player from Walmart for $20 and it would play the 4k video on my 1080p TV. I don't know if it supports 1080i.