Thanks, that was very helpful.Rules here: https://alison-chang.com/duya-legends-tour-golden-nine-standard-rules/
The Ko brothers explain the rules here: *snip* The youtube autodub to english worked great for me. This is the second thread in a row I've put one of their videos up, I should be on commision.
The key thing is you are eligible for 7pts if the 1 is on the table. So in the unlikely event of a player breaking and making the 2, 3, 4, 5, 6 but not the 1 then their inning ending, you can pot the 1 7 8 9 for 7pts. Or you can do a 1-9 combo etc.
Another weird thing is if you want to get 10pts, you have to pot the 9 after all the other balls on it's own. So if you break, make a ball, then pot the 1-9 as a combo. that's just 7pts.
You get 1pt if your opponent fouls. The 3 foul rule works differently- the fouls don't have to be consecutive. If you opponent fouls 3 times in a rack you win. But you get 1pt for the first foul, 1 for the second then 2 (making the 4 in total) for the 3rd and the rack ends.
The bolded part above actually seems disallowed as a table-run by the rules (bolded below):
Table-run: The following conditions count as table-run:
a. When a ball is made in the break, and the breaker makes a combination shot on the 9-ball during his inning;
b. When the No.1 and No.9 ball are still on the table, any incoming player runs out the table (excluding a combination shot at the 9-ball);
c. Pocketing the No.9 ball when breaking, which is also called a golden break;
It's not clear whether that means the incoming player can't do a combo on the 9 with their first shot, or any shot to get the 7 pts. I'm guessing the latter: to be a 7pt table run the incoming player must legally sink the 9 with no balls left on the table.