The methods auto-generated by DevForce for stored procedures are just helper methods to make query execution easier, they aren't required. In your code you can "new" a StoredProcQuery just as you see done in the helper methods, and then execute that query. Here's more information on the
StoredProcQuery.
As an alternative, you can use the EntityManager copy constructor to create a typed entity manager from the base EM, giving you access to your EntityQuery and StoredProcQuery methods and properties.