My main problem with Velcro is not that it won't hold the pedals in place - it's that somehow they lose their adhesion to the underside of the pedal, leaving a gunky residue. Mostly on pedals that have no flat metal surface but some sort of rubber material underneath.
you will have this problem with other systems like dual lock or temple plates.
not all glue is equal, some velcro/dual lock have better glue than others.
but the part of proper gluing your mounting system to a pedal sometimes includes just cleaning it, sometimes you must remove the rubber material.
once I had a pedal to which previous owner glued dual lock with superglue.
if was okay, until that dual lock felt off and I was totally desperate trying to glue a lock to it again.
