Another possibility: put US 70 on US 70 BUS through Smithfield (this would be consistent with returning it to Clayton as already announced). Decommission US 70 BYP and also US 70 ALT; make US 70 ALT a state primary highway through Pine Level, perhaps NC 270.How about Selma? Its bypass is short. They might as well extend US 70 ALT through Selma and keep US 70 on the bypass.
Since I-42 will use US-70 Bypass in Selma, I'd just decommission US-70 Bypass and call it a day.
There are two big differences between Clayton and Smithfield. BUS 70 through Clayton is 4 lanes and is on the National Highway System. BUS 70 through Smithfield is neither.