I don't see a reason to be toxic in ARURF(Or any other match, personally). If you look at my match history, I've been spamming ARURF hard to finish the missions. I've had an absolute blast doing it, and I've almost never "Focused" on winning. I literally pick a goal and aim for it. A goal like... Let's see how fast I can get Lulu and how far the enemy will chase me around the map.(Spoiler - They don't chase very far when you've got 1200 Movespeed and basically teleport past them.)
If you don't look at URF as something that needs a focus on winning, it becomes so much more fun. It allows for the most ridiculous things. Even if I'm losing, the enemy team could be at our doors in a 65-10 kill game, and I can have a blast by firing myself out past them and zipping past with 1200 move speed for them to chase me away. You can build the most ridiculous things, for no reason other than "This one effect on this one spell will be stronger". Or Deaths Dance/Gunblade Cassiopeia. Or melee range Ezreal!(The closer you are to your target the faster his Q resets, since the CD reset is on his. You can get it going super obnoxiously fast in melee range).
Win or lose, if you're zooming around at 1200 MS out running an ulting ghostbladed Yi as Lulu, it's fun. There's tons of other similar things that can be done - Focus on enjoying the games, not winning them.
Side Note: I've won more than I've lost, and gotten a ton of honors along the way by just having fun.
