Umarex Zelos Trigger improvements / mods?

Has anyone modified the trigger on a Zelos. I lighten the spring on the trigger rod and adjusted the screws for 1st length and pull weight. The trigger is now an acceptable 1.5 lbs, the 1st stage short, but 2 issues still exist. Overtravel, and a non-smooth somewhat gritty pull. All my other PCP guns have better triggers, R5M, Vixen, Marauder and GK1.

I guess you get what you pay for it was the least expensive of the bunch!