I'm currently working on a gamemode that would reduce stalemates by forcing losers to push out of last. Here's a quick overview of what it does.
Each control point your team owns generates 1 "influence point" per second. Additionally your team generates 1 influence per second passively. At 1200 influence, your team wins. Capturing last also wins the game immediately as before.
This means that if your team has less caps than the enemy, you want to remedy that ASAP, because if you just park the bus, you'll lose. Of course, this in turn means that the team that's ahead can park the bus, but this isn't as unhealthy because they've earned it by winning mid/taking 2nd, and the losers are far more motivated to push out without stalling than the winners would be to push into last in the current meta (they want to play it safe, so you see those long sieges and waiting for crucial picks before pushes).
And yes, I know pushing out of last onto spire is suicidal, but the whole idea for this gamemode is based on the assumption that if you've lost mid and 2nd, you'd better pull some miracle off if you still want to win.
It's still WIP, but you can download the badlands implementation here (it's completely contained within the .bsp, no plugins needed):
http://fakkelbrigade.eu/maps/5cp_badlands_a0.bsp
I'll make a prefab and post it to workshop soon enough, so if someone wants to put it in their map, they will be able to.