In October is the International Open in Virginia. It has tournaments in 9-ball, 10-ball, and One-pocket. It looks like only the 9-ball is WPA sanctioned.The pool player infrastructure falls on the WPA. They do have American 14.1 on the calendar, the flipside to that problem is , there aren't enough events through the year to make practicing 14.1 worth money.
The American 14.1 Championship seems to typically have 40-some players, and that's been dominated by Europeans now, since John Schmidt was the last American to win it back in 2012 I believe.
The Dragon World 14.1 is also dominated by Europeans.
I'm not sure what it would take to make it bigger. Maybe that pool-loving billionaire everyone keeps looking for. Someone should ask Elon Musk if he's interested.