> So whilst the result isn't a direct multiplication it should still be an acceptable use since the resulting code will actually be doing multiplications.

First, nope, if it's not multiplication it should not be using the * operator, period. Operator overloading is already overused and it leads to so much problematic code that looks fine to the untrained eye (string concat using operator+ being a famous example).

That said, you may also want to pass more options to the Mul node in the future and operator*() can only accept two arguments.

As another example, run the following Python code to see how python represents its own AST:

    import ast;print(ast.dump(ast.parse("2*PI*r*r"),indent=2))