On p. 20 of the rule book, it says "Starting with the Imperial player , each player takes a turn placing one obstacle inside the play area… After placing all of the obstacles, the Rebel player chooses which edge of the play area is his."

I was thinking FFG explicitly stated Imperials start because they are assumed to have initiative in all of their examples (and because in the starter set it would always be same point Rebel vs. Imperial squads, in which case Imperials have initiative). Thus, I was thinking it would generically be read as, “Starting with the player with initiative , each player takes a turn placing one obstacle inside the play area… After placing all of the obstacles, the player without initiative chooses which edge of the play area is his."

Someone over on BGG thought this didn’t apply to tournaments, but it seemed to me that it would/could still apply (given both sides can play the same faction and the same points, I thought initiative is what really mattered).

What do folks think would/should be the correct ruling for a tournament like a regional event?

Scratch that question… someone else over at BGG showed me I was looking in the wrong place in the tournament rules. I was looking under setup, but it is addressed under squad deployment. Seems clear from step 1 that sides are assigned up fron and can't be picked afterwards durring a tournament.