I almost read into your comment that using the macerator may get around using the proper dump sites which they don't. Black water is still back water and has t o be disposed properly even though it has been cut and scliced up using the macerator pump.
It is just a water pump to help you flush the tanks...
In fact using the Macerator may inhibit a large volume waste water flow if used all the time. I have only dumped my tanks a few time being connected to a Macerator. I tried it one time to pump up into an empty tote tank in the back on a truck bed once which worked like a dream.
Roy Ken