Each of the Silver press heads has independent off-contact adjustments. Actually, the adjustments on the back of the head do more than that. They allow for you to adjust the pitch, the yaw, and and the height of the screen. That's a pretty good feature.
I've got a press that doesn't have that off-contact adjustment like that. All it has is a single bolt affixed to the platen arm to create off-contact. (video of alternate press setup) That's a horrible idea. That press costs five times as much as the Silver Press, and they still didn't get that right. You really need each head to be independently adjustable because each different screen has different needs important to it for screen printing. One screen might need to be a tiny bit off contact, while another may need more. One screen may have the ink behave differently. That definitely happens since you have different inks in each screen. So, you really want the heads to be independently adjustable from the platen arms.