2006 Katana 750 Rear Wheel Force Comparison
Here is a comparison of the stock 10.8 kg/mm shock spring vs the correct for a 210lb rider 17.9 kg/mm spring. Notice the preload on Ratio #2 is at 20mm vs the 8mm on Ratio #1. When adding preload to get the correct sag from a spring with the incorrect rate you will end up with a stiffer feel at lower wheel travel but not achieve the correct wheel force at higher wheel travel for your weight.
Both plots are with identical leverage ratio and shock travel, Only the spring rate was changed.