Getting your limb pad perfectly square and on the same plane is critical, but so is making sure those limbs are milled properly and also checked for square is just as important.
After getting the limbs out of the form and carefully knocking the epoxy off the edges and straightened on the edge sander. You should lay them on the bed of the edge sander or a machinist table if you have one, and make sure that laying on edge that the limb butts as well as the working portion of the limb are perfectly square before running them through the drum sander to get them parallel.... Not doing this right is a common mistake for beginning bowyers, and they are fighting limb twist issues BIG TIME. especially in RC limbs. same theory applies to one piece bows, but you need a very flat surface with no twist in it to check the limbs.
just another though to chew on.....
Arlo