You will probably get varying opinions, but removing the upper cowl for preflight is something I don’t do. Just like most Cessnas or some Pipers where you just get a glimpse in the oil door, you use a flashlight and look around. I do pull my cowl at 25 hr intervals though. Others may wait until the 50 hr oil change.
RV6 built and sold
N199EC RV6A flying
Learn the facts. "Democracy dies in darkness"