Not.sure how the vented loop works on the output. Does that mean.poo water can squirt out when under pressure? You wont have the cavity to route these anyway. Just have cocks on the toilet. You can always shut off the cocks. And a high water alarm if you want to be doubly safe ( float switch/ bilge to piezo) in the front compartment. Its.not as.though yr leaving at a mooring and if u were u just turn cocks off.
Also maceraters clog. Like a lot. I have a cable snake and plunger on hand for unclogging