Rear loweing springs when up on hoist?

[Lux]

Originally Posted by dogsridewith

Lux. regarding correct terminology. Wouldn't the piece in OP's car needing shorter full-extension be considered a strut that combines functions of motion axis restriction (helps keep wheel pointed straight and only able to move approximately up and down), damping, and rebound stop/cushioning...where if one could get into the thing, all that would be required is getting some spacering under the rebound stop?
Once upon a time some racer guys might have installed a rebound strap (length or loop of woven thread) at each side to limit/adjust rebound travel?

You are right, although struts is a term normally applied to dampers used in a MacPherson geometry where it takes the duty of a control arm (lateral and thrust location of the steering knuckle), ball joint (top hat bearing for turning), and damper as one complete unit.

In the case of Yaris rear torsion beam suspension, the damper will only control the speed and travel of jounce and rebound. Lateral and thrust location are the duty of the torsion beam bushings. Toe and camber are fixed because the torsion beam and its mounts are not adjustable, but they will change in fixed amounts as the beam travels up or down.

You're right in that there are ways to jerry-rig a rebound stop, including rebuilding the damper with more shims (to limit its extended length) and tighter valves (to slow and stiffen its rate). Unfortunately, there are no notable or unique characteristics of the stock damper to make it worthwhile, so, generally, total replacement is more suitable and far less expensive.