As you can see in the pics, new calves do occasionally go under my rotational grazing system's single interior divider wires.  If they are small enough to go under the 32" high wire, they seldom get too far from mama so I don't worry about it.  They do NOT however go thru or under my 5 wire/middle-one-hot perimeter fences.

I don't mind if baby calves are not in the right paddock. They will come back to mama. I don't want them out on the road. A good perimeter fence keeps them off of the road.

If calves are small enough to fit under a 32" wire without being shocked I suspect they are also too small to really get much "creep" effect from getting advance grazing. They are almost 100% on mama's milk at this point. Besides, what grass is open to them is so good there is not a big difference on either side of the hot wire, at least for most of each day.  They may learn to go under just to have a place to lie down undisturbed in fresh grass. That's ok. They come back when mama calls them.