I admittedly lost an embarrassing amount of USDT into a Coinbase wallet, and Poloniex and Coinbase basically politely told me I'm SOL on their ends.
What's worse is that I can view the transaction in omnichest.info with the full amount of USDT shown in the wallet. However, in my Coinbase wallet, I'd only received pennies in BTC from the txn.
I haven't heard back from Tether support either. Oh well, at least I've still got my mining rig. Back to the Ether mines, I guess.