Great, this sounds like exactly the right thing to do if you're aiming
for APL2 compatibility.
Dyalog has to jump through some hoops when it parses 2//B, to treat
the first / as a function but the second / as an operator. APL2's
parsing rules are much simpler.
I'm not sure it has to jump through any hoops. My experimental APL parser returns the same result as Dyalog, and its parser is probably as simple as it gets. It's a simple left-to-right recursive descent parser with one token lookahead. In fact, I think achieving GNU APL's new parsing style would be much more difficult.
In GNU APL's case, it's probably the right way to go because APL2 compatibility is an important feature, but I don't think it's a simpler approach.
Regards,
Elias