Njnja 250 & 300 uses same shock. You're about 15-lbs heavier than me, so total weight is +35 lb for you. So should have even softer ride than me. Is your pre-load setting on middle or lower?
I've tried GSX-R shocks, but they're all way too stiff because of 4:1 leverage ratio with linkage vs our 2:1. So shocks are configured for heavier bike with less shock-stroke.
Sure, you can use jackstands under pegs. I usually just hang rear-subframe from garage-rafters to work on rear suspension. Other people have had good luck with hanging front or rear-end from ladders.
