Haven't even opened it (same as arenas before - which got me interested for like <100 games and also just as warmup) and probably never will.
This mode was made for those clowns who will throw the game and then call you out to do 1v1 to prove that their brainless decision in BR game was correct :D
Adding to that Respawn's ability to soft out matchmaking... I can only imagine :D
dingothe1 not sure how do you warm up for 3v3 with abilities and kinda randomness to it via 1v1, no abilities and limited environment... imo aim trainers / firing range is much more valuable way to train, warm up some skill. Most of the time only thing that needs warmup is your brain (ability to process information) and warming it up 1v1 in predictable environment vs chaos of 3v3 with 20 other teams is like warming up car's engine with a candle.