From your source:
“Despite what they are called, however, spoilers and speed brakes are used in the same manner and for the same purpose: to steepen the descent profile without increasing airspeed. They also can be used to reduce airspeed by holding the sink rate in check.”
“Deploying them allows an aircraft to descend more steeply without an increase in airspeed. (On piston-powered airplanes, they enable a rapid descent and reduce the risk of shock cooling the engine.)”
So your source (AOPA, nothing else !) says better than me what PZL104 an me wroted above:
- spoilers = speed brakes, despite what they are called.
- They are used to decrease speed and/or operate steepest descents without increasing speed.
Evidently, doing this needs you can manage the deployment to control desired speed. A toggle Deploy/Retract won’t do the job.
They are not talking about “use is restricted to a few seconds” or something similar. Simply because you need to be able to control the speed as long as necessary.
In French I would add:
CQFD
P.S. Thank you for proving me right.