I personally would NEVER pass a moving vehicle on the right (or any shoulder) unless it was an emergency maneuver. So I would answer "no" it's not good practice and go as far as saying it's unsafe.
I am curious about your question however. You mention the other vehicle is traveling at a reasonable speed. So why the need to pass? I was in a situation a couple years ago where I passed a vehicle on the left shoulder (divided 4 lane). Coming to an intersection about 2-3 seconds away at ~50MPH. As approaching the light turns yellow, both car and I following should be able to clear before turning red. Driver in front suddenly notices yellow and stands on the brakes. I brake hard but will not stop without impact (or laying bike down) so I get off the brakes and roll on the throttle and pass along the left on the shoulder. Wasn't my ideal situation but was the lesser of evils presented to me.