I wonder if it would be too casual to have precedence defined in terms of aliases.
I don’t remember what mechanism they introduced to say that /: is an alias of foldLeft, but that mechanism could imply that the alnum operator has the precedence of the symbolic operator. Possibly that assumes there is only one canonical symbolic operator.
Maybe the mechanism was to say that a symbolic operator has a canonical alnum name instead of conversely. So they should change that.