It would be nice to be able to select more than one feature at a time to constrain. For example when I have ten parts in my assembly that I want to constrain flush with each other I have to click face of A to face of B then face of B to face of C then face of C to face of D and so on. It would be much quicker to just select the face on each part and constrain all of them at once. Along with that if I end up having to delete one of those parts such as C I loose the constraints between B and D so I end up having to remember to connect them again. So it woud be nice if that flush constraint remained between the remaining parts after deleting the one part.