Is it possible that the oil control rings might be worn to the point that you're burning significant amounts of oil, but the compression rings still be good? Or do they typically wear out together such that burning oil and low cylinder pressure go hand in hand?
Rings generally wear at the same rate meaning that when it's time to replace one you should be replacing them all as they're not seating with the cylinder properly any more.
Burning oil does not always imply a loss of compression. Cars with good rings will burn oil due to bad valve guides or bad valve guide seals.
A compression test should help you isolate this issue.