I continued doing various tests and realized that my problem was something else, since the following code works:
#lang typed/racket
(module untyped-submodule racket
(provide a macro)
(define a 2)
(define-syntax-rule (macro arg) (+ 1 arg)))
(require 'untyped-submodule)
(macro 3)
Using a in the enclosing module doesn't work (a is required without a type), but macro works fine.
Getting back to thinking and trying.
-
Sergiu