So, T-Mobile's data logging and throttling don't work on a number of sites. Among these are:
For example, right now when I can't even stream a video on YouTube at 144p without it spending far more time buffering than playing, I can play the same video at 720p without interruption by accessing YouTube through ProxySite. Images on lolibooru and pexels load in a couple seconds where they would take minutes on other sites.

However, a web proxy isn't a suitable solution. I've tried SafeVPN and Tor Browser, but neither of those helped. As far as I can tell, it only happens on https sites, but it doesn't happen on most of them.

Any ideas? If there's any way I can take advantage of this even for a while, I'd prefer that to spending $150/mo. for 4G.