Vince and his boss? Were you talking to little Vince? 'Cause Vince the elder IS the boss. : )
That said, a 1.6/1.4 rim isn't as limiting as you'd think. The big limitation is avoiding low profile tires. You need that sidewall height to mask the narrow rim and allow for a decent profile. Dunlop TT91 120/80 and 100/90 12" tires mount up beautifully on narrow rims for example. Yeah the profile doesn't match what I get on my 2.75" rear and 2.5" front rims but it's still damn usable. When you try to use a 70 or 60 profile or shorter that's when they get real ugly.
Oh, next time you talk to Vince, tell him 'Kurlon' said 'Hi'. He's the guy that helped me a ton when I was taking mini's serious with my initial 70's development as well as convincing me to drive to New Jersey to try dirt out for the first time. Damn good guy in my book.