Hmmm... not sure how people haven't noticed this, but it would seem the library forks (I'm personally referencing the "Fox-like" 29er forks), use the axle-to-crown (AC) length as the L length, which is incorrect since:
AC^2 = L^2 + R^2 (basic trig...)
So with a rake (R) in the range of 44mm to 51mm, that makes the "virtual" fork in BikeCad ~3-4mm longer than it should be... which is enough to throw angles out by about 1/8 degree. Or if angles are matched, then linear dimensions then become out of whack. :)
Easy workaround is obviously:
L = (AC^2 - R^2)^0.5
... though BikeCad itself should obviously have a "switch" to define L using AC and R, or AC using L and R.