Yes it's been covered before
First thing to remember - cloud can break up, or it can close in. Licence privileges clearly state "Clear of Cloud and in sight of the surface". So - with those two factors thought about the best rules of thumb are:
If it's FEW or SCT then no problems - providing the holes are big enough to descend through (they will be if that's the cloud cover - SCT being no greater than half sky covered)
If it's BKN then
DON'T risk it. The holes won't be big enough to fulfill your legal obligation, plus if they fill in you're going to get caught out above, with the ensuing IMC descent that's going to require.
OVC - self explanatory really