Unlike bin serialization crates there's no need to compile any crate for the host to make formatting work (IOW there's no `Deserialize` trait here)
Even string literals are stored in ELF metadata! The target sends indices (1-2 bytes) rather than full strings; this reduces `.rodata` usage and xfer bandwidth
P.S. The 6us I quoted in part 2 could, in theory, be brought down to 2us if the data xfer took negligible amount of work but I haven't had much luck reaching the theoretical limit.