The thing is that Smalltalk do not have language constructs like loops or conditionals ifs/switch. Smalltalk also do not have functions only methods. There are only objects and messages.

Your infix functions would need to live somewhere probably in global scope with makes then no different than language constructs.

I would love to see new Smalltalk implementation that is not a Walled Garden. Making a Smalltalk impure is not a way foward imo. You work is interesting but what we need is Smalltalk VM on modern back-end like LLVM and better concurrency.