I've found that when I search and search and can't find something, it's because it was so fundamental a feature that it is automatically assumed people know how to use it.
What evidence do you have that T-Mobile is blocking your tethering after 2.5gb? Others have asked but it doesn't seem like that question has been answered. I have CM11 and have tethered like a fiend using the ROM's built-in hotspot feature, which the stock T-Mobile Account app doesn't even pick up on. Additionally I've been told that after 2.5gb, they don't block you, just throttle your speed down.
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