OK I can't resist offering one DIY trick for this, because it's really easy. I did this, and it flattens my beam out and reduces spill from the top.

Find a plastic Fresnel magnifier, something like this https://www.amazon.com/Full-Page-Mag.../dp/B001TLJXJ8. The full page size works best, but you can experiment with smaller sizes. Unscrew the lens of the headlight and trace around it on the magnifier, somewhere offset from the center, like a third or halfway up the page. (up from the center!) Cut the disc out, insert it into the headlight in front of the lens, and presto you've got a spread out beam angled down. If the shape isn't right yet, go further up the page and cut out another one.