My first experience with a course that I didn't design myself was Roosevelt Park in Albuquerque when it was still a trashcan course (late '85 or early '86). Really cool park with lots of hills and big trees and all the holes were reachable but only with my best throws. I had XD's and avairs (if I remember correctly). Played with a couple of local guys who said everything was Par 3 and didn't think much about it because all the holes I was making up back home in TX were mostly short Par 3 type holes.
A year or two later I played one of John Houck's events in Austin and he was playing with the idea of longer 2 shot holes, which he added to the temp tournament courses at Texas States Overall Championship (fall) and AquaFest (spring) in Zilker Park. Not sure if they were listed as Par 4 on the card or not. That got me to laying out longer holes here at home, which most of the locals didn't like. Probably because at the time I was consistently throwing much farther than them. Even though I called them Par 4, the others just wanted to play short, dinker holes where a 2 was likely.
When John H. started the Circular Skies tour series (maybe "89?), he was fully in on Par 4. The event in Carrolton had a couple of them, and acceptance was creeping in. Then in 1990 Old Settelers in Round Rock exploded onto the stage. First year was Texas State Doubles then after that it was called National Doubles and drew lots of the top players of the time. That course had legitimate Par 4's and Par 5's.