Ability to constrain multiple items at once, like setting multiple segments perpendicular to the floor (plane). Right now if 2 lines are selected and you choose perpendicular constraint then they are set perpendicular to each other but if you select more than two lines then the cursor waits for second object to constrain against. If more than 2 objects are selected then they become a selection set waiting for the second selection set which can as well be more than 1 element. Imagine that I want all the vertical segments to be parallel with both vertical planes of the Run. Select all the segments then choose parallel (parallel command should also allow to be invoked before selecting anything) then choose the second set (vertical planes of the RUN, added with include geometry).
@dan_szymanski