When I design a rib I make sure that if there is to be any sanding done it will be the rib, not the spar or trailing edge.
Also I leave the ribs 1/8 long because some guys like to notch into the trailing edge. Sure enough, I get some *****ing because they had to trim the length. How sad!
Plans can have some distortion due to the copy process or the weather so you have to do some "fudging" occasionally. Best to have the parts a bit "proud" as was suggested...