I usually do not bother- they look okay to me without. I find some ladders in 1:700 are not designed to bend steps.
I do bend the steps on 1:350, and occasionally have done short ladders in 1:700. I have a pair of tweezers with very sharp and quite long points. The points will go between the steps. Just grabbing the steps by closing the tweezers sometimes bends them enough, but giving them an extra bend to set them at right angle works, though it is hard to see the steps well enough to judge the angle anyway.