I only run the strap through the buckle after it has served its time as a toestrap and is now doing other functions. I use them as toestraps only on my fix gears where I want the guarantee that no matter what I do, that foot is staying on the pedal if I accidentally uncleat. This means every tighten happens while pedaling. It always seemed to me that having that button yanked through my fingers could hurt so I just drill one hole in the end of the strap, run 2" of polyester cord through it, then whip the cord sailor style. Easy grab. No harm done if I'm late to the grab.

Replacement straps - I go to Oregon Leather and have them cut me hide-long 1/2" strips.Drill and pop rivet them to the buckle. If I want black, leather dye works really well. They last longer, especially in the wet with Sno Seal.