EPT1.) Initial drone scout spots 2 zealots blocking the ramp, giving suspicious thoughts and goes for either fast evo/lair to hold off any 1 base toss attack.
2.) Overload "will" fly over even if it is a sacrifice to check and see if your teching or not. No matter how much you want to deny saying "i can deny these overloads", it will get the zerg players to stop droning and quickly get spores and crawelers with units to hold off any sorts of rushes.
3.) See double gas getting mined. The placement of the shrine really doesnt matter if zerg knows your teching into something. Their point of sacrificing the overload and doing drone scout in 4 minute mark is to see if your going to do all-in or pressure or tech and all-in. Don't assume every zerg will "drone" hard.
DT openings are like risking your game. Trust me. When i was playing protoss the start of season 1, I did tons of DT rush builds. I know your timings are like accurate for what any player below master will do, but any decent zerg will take a glimpse and play safe by being sure to get enough defence towers to stop your all-in off 1 base.
