A Wolff reduced power hammer spring does just that; reduces the poundage needed to cock the revolver. It does that with a corresponding reduction in energy to the falling hammer, reducing the energy of the hammer/firing pin to light the primer.
With hard primers or in very cold conditions, I will recommend you leave the hammer spring at a stock weight setting. An unwanted, Click! is not what you want when pulling the trigger on a hunting gun, a defense gun… heck, when shooting any gun.
A reduced power trigger return spring does the same sort of thing; reducing the energy needed to compress that spring with a corresponding reduction in strength to return the trigger back to reset.
The DA trigger pull weight can be brought down a bit with a new trigger return spring that is a pound or two lighter than stock. This will have minimal (if any) effect on reliable function for the majority of shooters. (A high-speed competitor may be able to “outrun” a lower powered trigger return spring because those guys cycle their guns so fast.)
An improvement in action smoothness, which IMHO is more important than a light pull, can be realized with light polishing of the trigger return slide, the area where the slide moves within the action, shimming any moving parts that may be rubbing on the sides, veeeery light polishing of the trigger surfaces, etc. I use 1000-1500-2000 grit wet/dry paper and a wood block backer to smooth things out. (Be careful not to remove too much material or round off any sear engagement surfaces.) Lots of dry fire helps, as does regular use.
I have numerous S&W revolvers with Wolff hammer springs and trigger return springs. These are K-frame Target guns. Others, like my N, L, K annd J frames have had just the trigger return spring replaced. All get the internals polished to make things smoother on my end.
All of these are just my opinions from personal experience, worth no more nor no less than anyone else’s. YMMV.
Let us know what you decide to do and how it works out. Good luck!
Stay safe.
