Originally posted by funkedup
Greater stability margins mean less tail lift or even negative tail lift in level flight.
Most aircraft have their CG aft of the aerodynamic centre where the lift acts and therefore have a basically upwards tail load for balance. Any wing camber adds a download and the total may be up or down, but its direction does not influence stability. This depends where the neutral point is, controlled by the size of the tail, which does not affect the tail load. So if you want a large tail upload, instability is unnecessary.
