It's well known and even advertised that it's all about the order flow data. Top Step even says something like "your trades inform our trades." The entire business model depends on that.

When performance/XFA/paid accounts are aggregate anything other than delta neutral, they must go with that flow (using hopefully a reasonably sophisticated algorithm) in order to properly pay out winners.

It's a brilliant business model. Customers pay the firm, the firm sees the flow, and the best customer performers are rewarded for it. They get real time flow and they know the performance record of every trader with those orders. Simply brilliant, more power to them.