I don't strap in standing up to do it faster. Plus I tend to take forever doing anything and will skip around my music at the top until the perfect song comes on, mess with my gloves, straighten my jacket, look at dudes then eventually ride. Plus I am super OCD about strapping in. I can see plenty of mountains and scenery when not sitting. I think strapping in standing up is a better connection with the boot and binding. You don't ride sitting down.
I have lots of days on the mountain and seldom strap in sitting down. I have never had a strap get loose from this method, EVER. A few times my boot came out of my old bindings, that was because the bindings were failing. After the 3rd time I bought new ones and it has not happened again.
IT AINT EAZY BEIN STEEZY