Depends on the aircraft type. I have seen a caribou on a 10 degree final to opposite end threshhold with a landing roll within those threshold markings.
With a swept wing jet airliner, with all other safety boxes ticked, I would consider continuing if stabilised aproach with target still within the touchdown zone, provided ROD not excessive.
PAPI is not God and I have seen military airfield PAPI installed for earlier touchdown zone. In my airliner, this PAPI target was all white.
I believe that fog can cause all white lights at lower angles. Greater caution might be needed during these conditions where PAPI might otherwise be considered useful.
A simple question but such a variety of responses.