jbrrp I also use a funk firm mat I had to get the 3mm one because the 5mm one I had was too tall for the Triplanar, not alot of room to lower the arm on this table. I had to get a board from Greece and drill it myself because no one in the US wanted to make one without sending the whole table to them which I thought was kind of weirdA thicker mat works in the Triplanar's favor as far as VTA goes; this sounds a little weird.
The problem in mounting an armboard to the Technics is that to be the most effective, the armboard must be of the same material (aluminum) as the plinth, so as to not vibrate differently from the rest of the plinth. In this way it imparts less coloration. I've seen a number of armboards sold on ebay, but none of them were built with any of the vibration issues really sorted. So we built our own. Since Triplanar is about a 15 minute drive, we've usually had Tri over to do some supervision of the mounting to make sure the arm was placed optimally.