Trying to use Mate is a shambolic experience - simply a waste of time and massive aggravation.

I have a shed and trying to 'design' custom shelving. (completed on paper/pen 20minutes). 12 2"x2" boards with 4 each at 3 different lengths. 5 hours of frustration of Solidworks. All 2"x2" boards are at weird angles to each other. No 2 surfaces will mate in any logical way. Corner/surface, surface to impossible