I ordered 4 brass spikes & sheet No-Rez from Danny on Thursday & items by UPS Ground were at my front door Monday! That's service for you!
I installed No-Rez & spikes to Rythmik F12G servo sub over the holidays. After 1st panel, it was apparent that notching No-Rez around 3-4 1" square triangular corner braces was going to be very difficult. So I went w/ whole pieces between corner braces, then filled-in gaps w/ No-Rez strips. Small pieces were applied to top of triangular corner braces.

I was quite impressed w/ improvements. Results per 80 Hz xover: even tighter, more defined detail, less coloration. SPL meter readings before/ after 2' directly in front of 12" speaker:
Sub stock cabinet (30 Hz- 80 Hz): 105, 105, 100, 100, 91, 99
Sub cabinet w/ No-Rez (30 Hz- 80 Hz): 106, 105, 102, 102, 95, 99
In keeping w/ Rat Shack readings, Denon avr-1909 Audyssey auto cal. adjusted from -0.5 dB to -2.0 dB