Hi there,
I too have installed the Lust lowering link for my T9GT. I had the same calibration fail after the install, which I did myself. Rode the bike for a few days. The back did feel quite harsh. I was going to try to "reset" the starting point of the bell crank, but suspected I had the refit the bell crank linkage wrong. I refit the crank arm the other way, and was able to successfully complete the calibration. And yes, the back end did feel more planted afterwards.