4Game

As a Turbo main with more than 4000 matches, I play it not because I don't have time for a long game (because I regularly play a couple of matches), but because I'm too fucking lazy and impatient to have to spend too much time getting big interesting items, or micro managing my courier to not get it killed, or needing to worry about not completing my items in the fountain, or griefing the carry because I took some farm for my Arcane boots, or being 10 levels below the enemy and not being able to do anything.

The problem about Turbo is that in many cases it punishes the sudden loss of momentum, and encourages turtling and jungling. Imagine this scenario that I've lived A LOT. You're ganking, winning fight after fight, you manage to get 6 rounds of kills on the enemy team without dying once, but the game is still balanced in networth because they've managed to get a little farm. Your team reaches lvl 23 at min 16-18. You take one fight that you lost and BOOM, the game is fucking over because they'll just do a single push midlane, Tier 2, Tier 3, Tier 4 and ancient. You don't have time to respawn because you've already hit 70 seconds. You can't buyback because the cost is too ridiculously high. The game is over, just because you focused on the action instead of patiently waiting.

So yeah, the idea is that the towers remained strong, and buyback costs stayed the same as in normal dota. It wouldn't require any balance at all. Valve has never balanced any hero around Turbo, so it wouldn't affect current metas or pro matches. You could consider it as an ability draft. It wouldn't require any hard implementation either, since it's literally just modifying two global values. It would be a mode with more risky action, greedy kill searching, and less chickening out and focus on farming.