It works great but I believe the Ohlins rear shock I'm using is too stiff spring wise

I started digging in the Ohlins documentation that I believe could be helpfull to other GSRs.
1)Rear shock springs
Most rear shock springs have a 57 mm diameter.
They come in three basic lengths:
1091 : 160 mm
1092 : 170 mm
1093 : 150 mm
The full number on the spring will be for instance : 1092-29/90
The last two digits give the spring rate in Newtons per mm.
Here 90 N/mm or 9.77 Kg/mm
You can find a full table of the available springs here:
2) Rear shocks and fork springs by bike
As it's very difficult to find the OEM spring rates on most bikes here's a usefull table of the spring rates Ohlins uses on their own shocks.