Right Andre, prior to the 6.7 engines, it didn't matter..
so, it looks like the MM does matter on the 6.7 engines. (didn't on my 08 f350 as I said).
of course, you couldn't change on the fly if you removed it, so that would have been an added value.. (my spartan didn't support chnage on the fly like the MM does)
1955 F100 460/c6, 3.55ls - 436 hp, 489 tq
2012 F350 4x4, DRW, 3.73ls, CC, LB, 400 hp, 800 tq
2013 Keystone Alpine 3720FB 5th wheel. 40', 15,500gvwr