Jack... Do you still need to use the original eyepiece tray along with the TPI?
I would think yes. The ep tray pushes the tripod legs outwards while the TPI assembly pulls the lower part of the tripod inwards. This will stiffen up the tripod considerably. A similar DIY solution could be done with turnbuckles but the TPI tray is pretty useful. Adding weight on the tray increases the mass lower down.