When in a match that involves switching teams between each round, if at the end of a round your character is standing near a vaultable object you will be able to 'vault' to that object while spawning in the next round as the opposing team. In essence, this means easy teleportation to enemy positions before the match even starts.
To replicate this exploit, play any match that involves multiple rounds and side switching between rounds. When a round is ending, stand near a vaultable object. Then, after the round ends and your character is about to spawn as the other team, press the jump key to vault the object right as you are spawning. This will instantly teleport you to the last location you were in the previous round. I have found this exploit can be done consistently and it is game breaking in many modes as I could destroy enemy caches within seconds of the round starting.