I think it would be overkill, Elizabeth
When it comes to sanitation plumbing especially, the simpler and more straightforward, the better. If you're more comfortable with a manual pump than a macerator, replace the macerator...but I'm afraid both would only create more problems than it solves, 'cuz you'd have to put yet another y-valve in the system to allow you to choose between the two....you'll use one more than the other, and equipment that isn't used often tends to deteriorate much faster than equipment that's used regularly. You could find yourself in a situation where neither one works.Your macerator will remain reliable if you replace the impeller annually and lubricate it very thoroughly with SuperLube when you do, and rinse the waste out of the pump after you use it each time.