_KermitI'm pretty sure Slin tried to push for a change like this (shorter rounds) like 6 years ago or some shit and was completely shot down. I remember watching him on stream talking about it.
Multiple people have come up with the idea and have wanted to at least try it out and have been shot down.
Well I'm sure b4nny is aware that some people can be a little close minded until something is demonstrated in front of them so it was pretty smart of him to experiment with potential ruleset changes at an event that everyone was eager to participate in regardless. 4 or 5 minutes seems like a good spot for the round timer. I've literally only seen the 10 min round timer come into play a handful of times a YEAR while constantly playing tf2.