i agree! it's been percolating for a very long time in my head. i was envisioning a paper that shows how traffic analysis can be used to identify activities in the encrypted stream and then a cbr patch to ameliorate it.

where it gets complicated is avoiding creation of new side channels. you need a very stable clock for pumping out the data and as you hint at, congestion control to avoid latency by actively adjusting the bitrate.

i was looking at doing this in the kernel implementation of wireguard, but those parts of the kernel didn't seem a good fit for this kind of time sensitive constant spinning algorithm.

if anyone is interested in this, would love to collaborate.