That 1.25 inches is just an allowance for the waistband. you don't want to bury the velcro under the waistband!

Couple of solutions...1.) make a narrower waistband! Ergo, move the velcro up a quarter of an inch....2.) make a slightly wider under-apron strip. It doesn't have to be exactly 3 inches wide, four-five-six inches are fine. I wouldn't make it TWENTY inches wide, eh?