I work in a tuning shop and wax tonnes of skis and snowboards daily. OP just go buy a SWIX scraper, they would super good.
I think a common misconception is that when "sharpening" your scraper, you don't taper it at all. you want a scraper with 90 degree angles and then you push it tilted forward slightly, it's pretty damn effective. A file in a vice works really well for keeping your scraper flat.