In Part 95, Section D, encryption is not mentioned.
But the Emission Types are limited, digital emissions are not allowed. (AM and SSB) are specified.)
In theory, you could have a transmission header / trailer in Esperanto that would route the message, and then the message traffic. But that sounds like a hill that wouldn't be worth the climb.
Indeed, only plain language voice communications are allowed.
ยง 95.931 Permissible CBRS uses.
The operator of a CBRS station may use that station to transmit two-way plain language voice communications to other CBRS stations and to other stations that are authorized to transmit on CBRS frequencies.
> I threw together a quick proof of concept of it working over HF radio.
I'm not aware of any HF bands you can use in the US without a license. And it is prohibited to use any kind of secret encryption on amateur bands.