Yeah, this one seems like the simplest answer. the redundancy of the plaintext HTTP headers included in each and every request can be exploited in order to

Yeah, this one seems like the simplest answer. the redundancy of the plaintext HTTP headers included in each and every request can be exploited in order to reveal the length of particular components ... so randomly change the HTTP header length by adding random sometimes-compressible data. X-whatever, or just change the ordering of header lines, or add randomness to the UA string.