maybe for very low ratings it's plausible?
1 elo per byte might happen in a tiny range
but at a useful strength it would break fast, that's what i think
I'd claim it would work on human opponents, but I think it would get banned from chess tournaments.
The problem isn't really well defined. Elo rating is assumed to be determinable independent of what opponents you face, so scoring 50% against opponents rated 1800 gives you the same information as scoring 26% against opponents rated 2000. In practice that's obviously not completely true, and for degenerate examples like the ones we are discussing it completely falls apart.