this link makes it seem like the EXTEND should be able to handle the transcoding. When recording a show my QNAP nas cpu is <5% but when watching live tv it hits 99%. Is there any way to watch live tv without transcoding?
https://support.plex.tv/hc/en-us/articles/225877347-Set-Up-and-Configure-a-DVR
I’m having the same issue. Any chance you found a workaround?
AFAIK, The extend in plex does not currently utilize the transcode settings for the Extend as there were problems related to it with liveTV playback.
They output the file as mpeg2 instead of h264 for now, which is why the CPU cant transcode the stream on the NAS.
I have played with the various settings for my Extend what I have found is that for recording it is best left with Highest Quality typically. This causes the Extend to transcode the stream to h264 before sending to Plex. For Live TV I tested using my iPhone 7 Plus. I found the best setting for Live TV was using the Medium Quality (540p) setting which caused the Extend to do the transcoding and provided the best stream to my phone ensuring that buffering was mainly eliminated and my server transcode process did not seem to be hammering the processor during the Live TV session. Unfortunately there is only one setting for the Extend setting in the Live TV & DVR settings.
I subscribed to Plex Pass in the hope that I could watch live TV without transcoding using HDHomeRun Extend. I am disappointed that transcoding is still happening for Live TV. When recording there seems to be a very minimal transcoding process going on which does not kill my machine so that part is fine. I’ll wait for that feature to renew my subscription 
I’ve tried quite a few things. when recording a show via dvr there’s no transcoding, and watching a recorded show via dvr there’s no transcoding. watching live tv always transcodes. i watch via ipad, appletv and chrome. all 3 transcode. i have tried a few different quality settings on the client side, all of them transcode. on the extend it’s set to ‘heavy’ per the plex instructions.
my nas box can’t handle the transcode so i had to move my plex to a server. this is the only reason i have it on the server so i’d really like to resolve this issue.
Anyone know if they’re planning on using hardware extend transcode for live tv?
I believe it does use the extend for transcoding, but the plex server is then transcoding again. You can go in the web interface of your hdhomerun and see that it is transcoding when you are viewing live tv. In my case, up until a couple days ago I could view live tv on roku clients using direct stream, but that stopped working a day or two ago. I think the issue in my case is that the roku client has updated and is causing plex to transcode, but I haven’t been able to confirm that.
