I have experimented with that, too, but in my case it also multiplies the number of potential actions. If I have 7 actions per timestep, grouping them into 3-timestep blocks means I now have 777 = 343 possibilities to choose from.

From what I understand, the OpenAI Dota 2 AI has a long-term strategy module which was mostly trained by imitating 60,000+ replays played by human professional teams. My problem with doing that for the Borderland competition is that I don't have any data source for replays of someone playing the game really well. You control 3 units simultaneously and it's 2 teams against each other, so I'd need 6 dedicated volunteers playing the game for many hours to create a reasonably-sized corpus of human replays. And who says that those people are good at it?