To confirm this was in fact the problem causing the high 1x vibration, a motion video of the foot was taken using Erbessd Dragon Visio video deflection technology. The resultant video helped demonstrate the problem to our client.
The video was shot using an iPhone 6, with no special lighting. The 30 second clip took 20 minutes to adjust in the Dragonvision software to come up with a good representation of the fault.
The floor underneath the foot has crumbled away, probably caused by how the initial product is introduced to the machine (high loads).