Plex channel tuning for OTA

I understand that Plex needs to transcode for Roku for OTA and DVR (mpeg2 and roku doesnt play that) but when i log into my account on my win10 pc it still transcodes OTA live and DVR even though my web browser has no issue playing mpeg2 - why is this?

Is there any chance that the 15 delay to change Live channels can be lessen some how? Tried 2 different pcs that are 8 years apart and the delay to load a channel is the exact same on a Q6600 as on a i5-3570k that just shouldnt be if it was indead the hardware causing this delay, but I am no expert.

15 sec delay to load a new channel