If there's blue sky available personally I just use it and go around them, much easier on pax, pilot and plane.
I had a similar scenario near Alicante the other week, about 8 CBs around so I turned left about 30 degrees for about 80nm and went around them, only to hear a colleague overtaking me driving right through them (ones that were providing just amber returns). I just don't see the point in taking any chances if you don't have to, I think it's kinda negligent to drive into developing CBs. Just my 2 cents. I can't comment on the ITCZ
