Va has several limits. My understanding...

It only applies to the elevator (not aileron/rudder deflection).

It should provide adequate margins for normal maneuvers for the airplane including normal training maneuvers, spin entry/recovery (utility), and aerobatics for aerobatic planes).

It should provide margins for control surface structural failure as well as stalling the wing before wing damage occurs...but I'm not sure that includes slamming the controls back and forth, full deflection.

It may also not apply to aileron/rudder manipulations...it has been clearly demonstrated that rudders can be broken off with large repetitive deflections.