the trem stiffness is directly related to the string gauge. If you want a stiffer trem, you would need to go with larger strings - which defeats the purpose of easing up on the bend pressure.
Mechanically, I have wondered why trem designers didn’t use an opposing spring to allow for easier string gauge changes without making the trem system be so far out of ideal. But, this is a different soapbox…
You need to either accept the soft trem or block/deck your trem and go with a lighter string to soften the bending. I blocked mine so it was fairly neutral rather than deck it and need to adjust the string height on the bridge: NGD: Strandberg Boden Prog NX6 - #19 by sequences