It appears it is no longer throttling the transcoder after X seconds and continues to transcode for the length of the video, but only when using a chromecast.
Steps to reproduce:
Use the offical plex android app
connect to chromecast
play episode, and choose quality “2 Mbps 720p”
I have this issue on an Ubuntu 20.04 LTS install, but can also reproduce the issue on a fresh docker install.
Added a screenshot with some proof.
You can clearly see the first 3 chromecast transcodes are way past the " Transcoder default throttle buffer " of 60 seconds. (1st and 3th all the way done, second is still transcoding.. )
The 4th “Plex Web - Chrome” play however does respect the transcoder throttle buffer.