So, I think I have it straight now.
There are two outcomes (Both in BdyCM 726-43-01):
1. Changing to 0404 makes the horizontal lights permanently amber, however, they do not blink when you signal (i.e., signals non-functional) and hazards also non-functional.
2. Changing to 0101 makes it...
I just did this yesterday and am THRILLED.
To confirm (as I was not sure re: the 02-->01 or 02-->04 was a revision): I changed both to 04 and not have the horizontal amber lights.