Well.. got my Tex. Only needed a single layer of Crack Seal to create a perfect seal between the PCB and the aluminium base. Tearing the ribbed Crack Seal ribbon down the middle (4 + 4 strands wide), it press fit between the milled aisles. The thickness requires seating it firmly to the base, otherwise, there may be a gap in the middle sufficient to preventing screwing down the middle of the PCB. Tightening up the screws and the PCB seats into the malleable but dense putty like sealer (which does not dry out -- I've used it in audio isolation mods and the substance remains malleable for years). It can easily be removed as its surface is only mildly tacky -- doesn't stick permanently. It is dense (adds more weight to the keyboard) and deadens any vibration. My Poker 2 feels like a completely different keyboard: lovin' the Reds even more.
Word of warning: when you get the PCB/plate screwed down tight, it creates a very solid contact with the Crack Seal.. the ribbed material flattens out under pressure, even if it is less than a mm. That makes removing the keyboard assembly tricky as you have to pry it off the semi-tacky material. I don't plan to do any mods requiring access to the PCB to desolder anything so, barring failure of a component, it is staying as is. If I were to do this again, I would line the top of the Crack Seal with tissue paper.
