I think the closest I have to a line would be internal routing through the headset. Complicates things for zero benefit. But even then, if I found an otherwise cool frame for free that had internal routing through the headset, I would be tempted. And maybe it would get setup with external routing anyways.

I'll be excited the day I find a functioning electronic derailleur in the scrap bin. There has got to be some way to rig up one to be controlled by an old friction shifter.