If you replace it with a SeaLand T-series diaphragm pump, your maintenance concerns will go out with the macerator. I replaced mine shortly after getting the boat (in 2006) and have had -0- ZERO problems since, and we are aboard full time.
One caution, macerators are usually piped 1", the SeaLand is 1-1/2" and should be piped full size. That usually means the thru-hull is too small. Running the diaphragm pump with a choked down discharge can create back pressure that may cause the duckbills to reverse, and the pump won't pump. It can be remedied relatively simply, but it requires removing the duckbill and returning it to its normal shape. That generally means working in waste to get to the duckbill, so you'll want to avoid that situation.
It's not uncommon to have a full-size 1-1/2" thru hull for a direct overboard head connection, since it's rarely used, re-plumb that for a diaphragm pump.
Yes, it sounds like a lot of work, but once completed, you've eliminated the maintenance and breakdown issues with macerator overboard discharge once and for all. Your cruising style will determine if it's worth it in your situation to be rid of the macerator liability.