Lasers? What I don't understand is; what's so hard about setting up a chronograph?
First, you set up a target, at whatever range you choose. Then you set the screens, or the box if you're using a chrony, on the tripod out in front of the gun at whatever distance that's dictated by what you're going to be using that day. Magnum rifles and handguns need to be at least 15 feet in front of the gun.
Get back to your firing point, then sight past the screens/box to allow clearance and line up the screens right left and inline with the bullets path. DONE!
My pact chrono is not too critical about exactly where the bullet travels above the screens. Anywhere from 6" above to 18" is fine, and it can be off center by 6" if it above by a foot. I do NOT use the diffusers.
My question is; I see a lot of reference to some using levels to tweak the screens. Why? Is this necessary? I try to have the screens parallel to the ground and bullets flight. I can't see why anything has to be perfectly level.