I am sure you could, but a true leak down test requires a minimum input PSI, and uses a calibrated gauge to give you an answer (some systems read in % leakdown, some just “good”, “marginal”, “bad”).
I guess it’s not clear what you might do with the information you collect.... how do you know if your cylinders are truly bad without measuring the leak down properly? How do you know the status if you don’t check all cylinders and compare them.... although you have some indication based on your compression test.
If you are able to hear leakage, and (best case) it’s only coming from either intake, or exhaust, or both - I guess there is a chance that the problem could be corrected by removing the heads, and performing a valve job.
I am sorry - I didn’t go back and re-read your thread, but on your compression test, have you put oil in the offending cylinder, and repeated the compression test on the low compression cylinder? If compression goes up, that may tell you if you have a ring sealing problem.
Again - I applaud you for getting your hands dirty. I found a home leak down test on one of my cars was very unsatisfying.... I had too many questions about my technique, and it raised more questions than it answered. It was probably because it was the first one I did, and I have no experience to compare my results with.
And in the final analysis - there are only really two (maybe three) answers.... leave it alone, rebuild the engine (or maybe redo the heads alone).
Anyway - good luck. I am trying to be helpful, not discouraging. Give it a shot. Let us know what you find.
Keep all those parts organized!