I looked at a couple of the YouTube videos earlier.
From what I see, the actual trigger spring is what it is. not really lighten-able. And while polishing the moving parts "may" help some, the way that the sear works, it's up against the heavy piston spring. Therefore, while smoothing the sear step may help a tiny bit, there's no way to "fix" the weight of the piston spring weight on the sear parts.
Possibly shortening the step on the longer part of the mechanism (sear arm ?) will help a little, I also see doing that will also shorten the life of the part (name ?) that controls the action of the piston spring, part of the sear. It may wear out prematurely from having a smaller step, with the same high spring load.
Plus, the location that the folks in the videos are reworking...are...modifying the WRONG location of the sear !!
One guy replaces a long spring with a lighter one. Not sure, but I think it looks like it helps keep the sear in battery (ready to fire). Not positive that a lighter spring would help a lot.
Overall, it seems like a lot of work for a very minimal amount of trigger pull lightening. And all on an inexpensive gun. To have gunsmith do the work, would cost four or five times what the gun is worth !!
Mike