lol@McGuyver clipless. That's some sketchy looking stuff right there.

It's well worth sucking it up and getting some stiff soled MTB shoes imo. My first pair of clipless shoes were a semi-casual, flexy soled shoe (Specialized Taho), and each pair of shoes I've bought since have gotten progressively stiffer. I don't think I'd ever go back to flexy soled clipless shoes.