This seems to be a protocol to coalesce multiple payments between a single sender and receiver, provided that the sender is willing to commit money up front. It

This seems to be a protocol to coalesce multiple payments between a single sender and receiver, provided that the sender is willing to commit money up front. It does nothing for the case where a single sender wants to send one-time payments to multiple receivers, nor the case where many individual senders want to send to one receiver. In those cases it would only add overhead. In the case of Brave it doesn't help them much since there is no real-time requirement, so they could accomplish the same by increasing the time between payouts. With some engineering they should be able to support literally thousands of users before they need to take everything off-chain.