It's slightly worse than that: a payload can be any 8-bit data... except a LF character. Which is to say, you will need to either escape or quote it in some way, which is to say you are on your own.
It might have been cleaner to specify base64 encoding or length-prefaced payloads (say, 16 bit int preface indicating length in bytes). As it is, you are on your own.
It might have been cleaner to specify base64 encoding or length-prefaced payloads (say, 16 bit int preface indicating length in bytes). As it is, you are on your own.