I'm using Cross brakes on my bull horn too, but it's not chewing up my brake cable.
Is it ripping the plastic housing or the actual able itself? I don't think the levers are the problem here, probably have to do with the cable itself.
TT levers are fine if you ride on the horns a lot; if the end of the bars and your hands are quite a distant away, then it might not be a good idea to have them.