Duel tournament.

I'm in favor of duels. I wouldn't say that few people are interested. I think people will gather (there are still people in the counter-hero theme in duel mode), because playing a few standard duels takes significantly less time than playing maps or RTA.
Regarding the conditions, here's an option:
1 game. Allow the opponent to choose 6 (or another number, at the discretion of the organizers). Player 1 chooses the hero first, then player 2. (cannot be changed).
2 game. Swap heroes.
3 game. Allow the opponent to choose 6. Player 2 chooses the hero first, then player 1.
4 game. Swap heroes.
The conditions are, of course, not new. But in my opinion, they are quite interesting.