I noticed that the videos in Youtube looked much better on my new phone then on the previous phone and thought that the Youtube app was defaulting to the HD stream (previous phone had really crappy WiMax, new phone is LTE @14Mbps even inside a large warehouse). After toggling it on and off to be sure it was indeed off, it appears that it still is using a higher bitrate stream probably because of the great LTE. What is strange though, is that last week, Youtube was averaging 150-200MB a day after watching a couple of videos. This week, after toggling HD on/off, it's nearly 3-4x as much and rapidly using up my data for the month. The "regular" stream also doesn't look that much different at all from the "HD" stream, so it could be it's stuck on the HD stream because of the high bandwidth my LTE connection has (or something else).
I want to use a lower quality stream to conserve my data, but have not been able to find any way to do so within the Youtube app, or via a Xposed module. Is there any way to choose the video size at all on a Android device? I'd prefer to stick with the stock Google Youtube app (via some external control/option?), but if I have to use some other app to do so I will.