That would be awesome. I could blow through my monthly data cap in 0.68 seconds...
From what I can see and from the Sprint CTO's comments, the deprioritization happens on radio layer working on slices of around 30ms. If you are near cell edge, the scheduler will assign you less physical resource blocks. This deprioritization will affect you much less if you are near the tower as higher orders of modulation and less error correction plays into it. (Think out of a possible 100 or so blocks you could be assigned in a given timeframe, the blocks can either be slow due to poor radio conditions or fast)
From my year or so of having a dedicated testing phone on T-Mobile, I can feel confident in saying what they say is true about speeds only being affected on congested sectors (not the full tower or region). Sprint I haven't had as much time with so I can only go with what they say is the case.
I'm still on the "new verizon unlimited plan" which is the same that "beyond unlimited" provides, just at a cheaper price.
Then one day I got a text saying I had used all my data for the month, and I thought this was quite strange.
I logged in to see the usage, and AT&T gives you an itemized bill showing data usage almost minute by minute — I think the resolution is 5 minutes intervals.
Lo and behold they claimed I used 22GB in one 5 minute interval at some random point during the afternoon that day.
I called about a half dozen times to complain and try to get it adjusted. The agents would say crazy things like, “well were you watching a video?”, or “did you download a large email attachment?”
It didn’t matter that the iPhone they said did the download showed totally normal data usage stats on the phone itself. It didn’t even matter that moving that much data in 5 minutes was technically impossible. Even when I finally got an agent to admit it must be an error and that it would be impossible to move 22GB in 5 minutes, they said they would escalate the issue and then nothing ever happened.
I never got those rollover data bytes back, and ultimately had to switch to an unlimited plan to protect from the fake overages.
So I do worry about massive theoretical maximum throughout resulting in obscene charges with no way for the customer to prove the data transfer never happened.