From the primary author of GCC-IA16: "This is true of the Mentor version. Since then, TK Chia has made some patches to add far pointer support. I haven't tried them yet and don't know where to get a binary (perhaps I'll try to make a new release at the start of April). I have heard that the FreeDOS folks have had some success with Chia's version and can now use that to build instead of Watcom, so if you can track down one of those guys they might have a good lead. Searching twitter for gcc ia16 might be a good start. "
My personal advice is to try to work within near pointers. Far pointers is something you do because you have to, not because you want to.