I have no way of knowing whether or not Garmin intends to add truck-specific routing options to Garmin Mobile PC, but I think Garmin should. A large screen of a netbook or a laptop fits into a large truck, an RV, or a motorhome much more than a small PND does.
Perhaps users of Mobile PC could
contact Garmin and request or suggest large vehicle routing be included in the next version.
P.S The above linked Garmin support page doesn't display all options correctly on the drop down lists if viewed in web browsers other than Internet Explorer.