Us Wings3D users are lucky as wings units are EXACTLY the same size as blitz units
That's what all programs do. It isn't luck. Blitz doesn't care wether you use meters or kilometers as your unit of measurment. It see something is 1 unit wide so makes it 1 unit wide.
Create a cube that is 1*1*1 in ANY 3d software and it will be 1*1*1 in blitz.