Their isn’t one way to make a flat head screwdriver. Some a chisel and some are slots. The slotted ones are better but more expensive.
Both still slip from the screw and are a pain to manually screw (slotted less so).
Pozi is the best + type screw. It’s pretty much standard for UK construction. The only time a different type is used is sometimes Phillips for plaster board or external hex and internal torx for long or large screws.
Don’t think controlling the phase of such high power lasers is feasible, high frequency makes this harder than radio waves. These lasers are often fibre optic, which are easier to pump to very high levels without overheating. They are then combined to get even more power. Trying to control the phase across many lasers with very long path lengths before the output would be incredibly difficult.