Not sure your premise re: no cycling-therefore no leak, is correct.
My a/c didn't work last year, compressor was not cycling, and all it took was a small recharge (no leaks detected).


98 Mystique LS v6 atx 110,000km
97 Contour LX v6 atx 125,000km
stock CD on LS, cass on LX
spoiler, tinted windows on LS only
4 wheel discs on LX only
All other available options on both