I asked them if we would have to rebuild our entire panels if
we purchased the larger 5" version and they said no, the size
profile would be the same as a KLN94 stacked on top of a
KX155. So my response was "then the 5" version would
absolutely have the traditional Com/Nav but that the 3" may
not". They both agreed.

Excellent!

But it looks like the 3" is a go, and the 5" is a maybe.

Excellent, again!