I'll put that on my project list, I want to look at the pump mounting anyway. On our first dry trip with the X213 the pump was audible but not obtrusive. On the second trip it made the kitchen faucet shake and was much louder. Purged the lines on every faucet, including the outside shower, but no improvement. I'll make sure it's mounted well, try your method, and maybe even grab an accumulator since they're so easy to attach and are not expensive.
2016 X213 ⇝ Eq10K ⇝ 2014 EcoBeast