I'm fairly confident that the new reddit React implementation can be improved in performance by a factor of 3x to 10x. I would be interested to hear others who have good reason to explain why not. I can certainly imagine React-like systems that are capable of statically determining DOM influence sufficient to make comment-collapsing negligible.
Do you have any details on the experiment procedures? E.g. hardware, training time, loss curves? It is difficult to confidently reproduce research without at least some of these details.
Wouldn't you normally mix down on the receive side for better SNR? Doppler should be pretty negligible, so if your LO tracks the output the receive side could probably be an audio ADC.
Power on the output side is the big one for sure, however. Also I'm not sure the transducers cited are anywhere near big enough.