During my training, I was advised that TS is a no-no.
I was told not to go within five miles of a CB, not to insist on staying on the ground whenever there's a PROB30 CB somewhere in the same county!
If the forecast is for embedded CBs I stay on the ground. If you can't see them you can't avoid them.
If the forecast is for isolated CBs, which you have a reasonable chance of seeing and avoiding, then I go flying. And on occasion have had to change my planned route to avoid thunderstorms, which I've seen from many many miles away.
It's in between that's harder - when they don't actually use the "embedded" word but also give the impression that there are more of the things closer together than justifies "isolated".