Overflying the cumulus can also work if you know the clouds thin out over lower ground.
This actually crossed my mind briefly, but I didn't know what was waiting on the other side, and I was afraid of getting stuck above the clouds. Of course later I realized the clouds were generated by the updraft on the upwind side, so subsequently fewer clouds were on the other side. Next time I'll be wiser
Forecast, reports and satellite will give an indication of where the clouds are. Mind you, in the mountains, afternoon weather tends to get active. There's a reason for "Alpine Starts".
You need to learn local weather patterns and fly when the weather is in your favor.
Overflying cloud you do need fuel to turn back to good weather if you can't find a way down. Just be very sure it won't close in behind
If you seriously screw up the drill is to get over low ground and high ceilings before thinking of a descent. ATC needs to know. If all goes well, the paperwork will be waiting
