Question about Roborock S7 Max Ultra

Hello, I don't think so, because as far as I know the S7 has a removable water tank. The S7 Max Ultra has an integrated water tank and a port to fill it at the docking station. The charging ports may also be different, but I would have to research that to be sure.
However, I would say that the S7 is not compatible with the docking station.