Other than multiple cylinder model engine - I don't see a real application for compression tester or leakdown on our little gassers
Unless every test is with same oil film, the results are all over the place.
power is NOT related to cold compresion.

Consider the Dykes ring -
My 160J ZDZ is almost impossible to move thru compression -just holding the hub
My 50's are pretty easy to turn and leak a fair bit but are real power houses
as long as the rings seal on the downstroke -you get full power.
On our hot rod engines - we used the gauges to se RELATIVE cylinder performance

It was never a secret when I broke a piston land or ring on a run-

one quick cycle of the starter motor and all was revealed .