As I said earlier. For pros, the most likely thing to stop a run is clusters (after they make a ball on the break) not missing a shot. Higher chance of having clusters on 7' table.
For an amateur it's a missed shot. Amateurs miss many more shots on 9' than 7' tables.
So for pros I would expect higher numbers of racks run in a row on a 9' table. For amateurs the opposite.
It also follows that overall pros will have longer runs so I would not be surprised if the most racks of 8-ball run in a row was higher on the 9' table.
If running racks meant something other than bragging rights there would be a lot more and higher verified runs.
Danny medina at Dubbs Pubb in Denver ran 19 racks of 9-ball. That was how many it took for all the players to get out. Then he quit without missing because he didn't want to play for free. (That's the story anyway. I wasn't there)
So what scenario would there be that a pro would run 12+ racks of 8-ball? Nobody plays ring 8 and there are no bar table 8-ball tournies that have races longer than 9 or so.
If someone put up minimum 20k for a video verified 20 rack run. Or the highest run by a certain date gets the prize - there would be A LOT of high runs. And the promoter would have a lot of video to sell.