Blimey.
Carrying such faults is all very well until you have a real in-flight emergency; where even something like a U/S PTT switch stops being a nuisance and starts becoming a real safety issue.
A U/S APU is a fairly common nuisance, but we once had a Gen 1 failure during the cruise, which we solved by starting the APU and using the APU GEN, (and GEN 2), to get us home. Without that, we would have had to land at the nearest suitable aerodrome and wait until a new GEN 1 could be shipped and fitted, at huge cost to the airline, compensating the passengers etc.
I left one airline, partly because to get around the intercom boxes not having switchable live mics, we had to use elastic bands on the ACPs to hold the intercom switches open.............. not good to lose comms if the elastic band pinged off during an RTO or EFATO.