If this happens to scaffolds before the trees have filled the allotted space, then yield will not reach desired levels. Always head to an upright bud. Under very low vigor conditions, the shoot developing from the upright bud may be desirable. However, under most conditions this upright shoot is removed in favor of a more outward growing shoot. This heading will reduce the fruit potential by reducing the number of future spurs.
Large clothespins work better than standard clothespins.
Don't over prune. Leaving lots of limbs helps the lower scaffolds to grow more outward and less upright. My current thinking is that with dwarf trees, the leader will be maintained. Because trees are smaller, the amount of shaker force transmitted to the trees should be less, so leaders should be maintained adequately. The jury is still out on this.