Remembering our physics we know that a = F/m.
With that in mind, I figured one of the best ways to reduce vibration (which is proportional to a), would be to increase the mass of the APM. To that end, I taped together a stack of 4 US quarters and sticky-taped that to the underside of the APM.
So now I have my APM supported by 4 pillars of 1/2" Dubro with a stack of quarters stuck to the APM as a mass damper. Judging by the raw logs, this seems to have smoothed things out quite nicely.
Can anyone see any drawbacks to this approach?