Can't always do that, Crab - some jobs involve being close to other, lower powerlines then crossing taller ones.
Our rule is to identify the limit of exploitation toward the higher line, stop, climb and cross the higher lines when in level or climbing flight (not always at a pylon, but with both crew confirming we're above the highest point of the 'threat' line) then when tail confirmed clear descend and resume work on the lower powerline.