Update:
The local room had a small Banks tournament this Sunday. $20 entry, $5 greens, and an optional $10 and $20 side pot. The tournament being Banks was my idea, and I added money to the pot, so the room owner let me structure the format of the event.
Most of the players in our area of Philadelphia suburbs have never played Banks, so I was expecting a lot of weaker players that would take a long time making banks. Thus, I chose 7' tables to keep the game moving. The room has 8 9' Diamonds, and 6 7' Diamonds. We did short rack banks, not full rack. We did double elimination, race to 3 on the winner's side, race to 2 on the loser's side. The finals was going to be a single race to 4, but I later changed it to a single race to 3 (1 week before the tournament started). I changed it because one of the better banks players in the area and myself played 6 games that night, and it took forever. Each game turned into a safety battle. I said to myself "we both know how to play banks, and if we took this long, IDK what the rank beginners would do".
We really didn't know if 4 people would show up, or 20 people, as Banks tournaments were a complete unknown. In 30 years of playing, I've never heard of one in Philly. One pocket, however, is popular in our area.
I didn't want to introduce a time control to this event, as it was more of a test just to see what would happen. Banks is my favorite game, and I'd like to do this again maybe every other month or so.
We ended up getting 16 players. Skill range from low 400 to high 600. The tournament was open, no handicap, no skill limit cap. A few of the players were Banks veterans and have cashed at the DCC. Half the field probably never played a game of banks in their lives, but are avid pool players and definitely bank enough during regular 9 ball to know a little.
I'm super happy we didn't have a "true double elimination". The player in the finals from the winner's side was not happy, but that was fine by me. Having a climax to the event, and half the players still there watching the finals, was way better than a true double elimination that would have taken another hour and had zero crowd. If I'm ever a full time TD, I'd ban true double elimination. The finals went hill-hill.
I kept track of the match lengths for round one, but did not afterwards. About half of the matches were under 1 hour. The 3 longest matches of round 1 took 1:35, 1:35 and 1:45 minutes. The tournament started at 3:00 pm, and ended at 11:30 pm.
In conclusion, I think the event ran smoothly and was ok without a time control. If the races were any longer, it would have been too long of a day.
If we do it again, we might try single elimination on the 9' tables. Or, keep the same format. I think double elim on the 9' would be too long, unless we made it race to 2/2.