I am not very familiar with the switching at SAS, but I know at Spokane for the Builder, the road crews do it. If a switch crew rather than a road crew does it at SAS, they'll get paid a minimum of 8 hours work irrespective of the time it actually takes, IIRC. Restrictions on switching would tend to be more a union agreement thing than an operating rules thing. As long as a crew is qualified on the territory used in the switching operation and is not pushing hours of service limits, they could perform the switching under operating rules.