I think it would be good to shoot the current dose and let him earn the reduction on his own if he is going to. I won't be able to stay up with you, but you can update your subject line with the numbers or to ask for help. Good luck.
Most people here either follow the Tight Regulation (TR) Protocol or SLGS (Start Low Go Slow). Both of these list a number the cat needs to go below in order to earn a reduction. I don't know if you've had time to read about it or decide if you are going to follow one of these. With TR the cat needs to go below 50 and with SLGS below 90.
Here is the Sticky for the dosing methods:
http://www.felinediabetes.com/FDMB/...-low-go-slow-slgs-tight-regulation-tr.210110/