In my humble opinion that board is like a ship to someone your size, with your foot in the back strap in that position I'd say you would never get your front foot in, and conversly if you start off with the front foot in you'll find the back foot is way out of position. Most modern small boards these days are heavily biased towards front foot preasure and the back foot is used for control and you guessed it to prevent catapults, I'm not sure on big free ride boards but as someone else mentioned the riding position is out to the side not to the back therefore your back strap really needs to be more in line with the front one otherwise you will always be out of position. With your board you need to be pushing with the front foot with a lateral bias to counterbalance the sail so to sail it properly you need the front foot in. My opinion only as my experience is mainly with smaller boards
I always go front strap first.
When I was learning to use footstraps, what I did is position both feet just in front of the straps, so the back-side of my foot is touching the front of the footstrap. That way its really easy to slip feet into the straps without disturbing the balance of the board much. Helps get rid of the issue of catapulting etc.
