Is it true cut springs mimic ^ spring rate

My shocks suck. I'm 190lbs riding 1970s era technology with my damper rod suspended 96 shadow 1100 and I feel like a sitting duck.

Most cruisers sold these days have the same under sprung and simple damper rod design.

The result is unnerving in today's metro traffic.

Short of buying springs and valve emulators, has anyone cut their factory springs and thrown in some PVC spacers to boost functional spring rate?

Maybe heavier weight oil? I'm looking for opinions before I start chasing my tail!