Regarding overfly, either directly or with a little lateral, beware of the OAT temp changes. If you have climbed above an inversion this may put a lid on the CB development. How strong is the inversion? Can you see it. As you approach the CB what do you think your vertical clearance is and is the inversion maintained?
If the CB looks like it might bust the inversion then watch out!! It's quite common to have an absolutely billiard table smooth top. It's also common to see a little mound trying to break free above the lid. Are the clouds pure thermal: what's the time of day? Growing or dissipating? Are you over mountains, perhaps orographic, or over flat lands/big cities perhaps thermic, or over sea. If they're frontal that's another matter about their development.
These are questions to be asked as you are approaching and spot them perhaps 200nm away and have 25mins to assess. It's astonishing how fast they can grow, but also how fast they can disappear when conditions change. Much will depend on your type a/c. If a turbo prop stuck in medium levels, watch out. If a jet flying with performance to spare perhaps you can use it, but if near your top limit you are like the TP at medium levels.