Finally got out to a launch, testing this plastic motor retainer on an H410. In the first image below, you can see the motor installed before flight. It looks crooked, but that is just the yellow cap. And the second image shows the retainer after a flight and recovery. There was no damage, just a bit of soot. This shows that the retainer is fine for even small HPR motors. The only test remaining is to see how long it lasts.