I have started the next round now. I hope I didn't make any mistake in the seeding.
I have decided to take all players from last stage to the next one. In the future I'll replace those with a negative overall score (for timeouts). This is not too harsh, I think, it shouldn't be too serious, either. We're all here for fun.
I have tried this time to start four games each group such that every player plays two games and two players each game have three. Unfortunately, I noticed that the seeding algorithm isn't always consistent, so this didn't work out for the first league, for example. This is all manual work, so bear with me if it didn't work 100%. Any suggestions always welcome, of course.
So now, have fun and play!