tor man page doesn't mention isolating between socksports

If I set SocksPort 9050 and also SocksPort 9060, then if I understand correctly, Tor automatically isolates stream requests that come in on the different socksports.

But the man page doesn't mention this level of isolation. Maybe because there is no flag for influencing it?

It sure seems helpful to have a full sentence in the socksport intro stanza explaining what gets isolated by default, and what can be isolated by changing options. Or maybe there is a better place to put that than the socksport section?