PoE Firm-Letterhead918 builds

Hey all, so far this league has been crazy, especially with the new league mechanic, I've been able to juice like crazy. First time running splitting steel and was wondering what the final things I can do for the build, or if would it be worthwhile to start a new one. I could roll better implicit on gear, and probs use better charms but then I'd be investing heavily and the reward ratio isn't the the highest. Any advice?