WX radar does take a bit of tinkering, depending on the radar. I've flow with pilots who also were heads down at cruise and flew through the top of a cell. Coming back from Narita to Anc saw UPS fly shack center through a cell. Then they decided to deviate, lol. Pacific flying takes a bit more to avoid the cells. Lots of rain and the storms aren't always as rough as a thunder bumper in the US but it will still upset your cart service at FL350.