How do you tax with Vertex and Contract Billing

We are using the Tax Link Connector to Vertex and the Vertex 8.0 database with E1 9.2 (tools 9.2.2.5) - when we create Contract headers (F5201) and detail lines (F5202), we're trying to determine the heirarchy for where it pulls the tax.  Where does it start and what level of detail overrides the others.

We WANT it to tax based on the JobSite address which is the F0006.MCAN8.  We'd prefer to AVOID customization in lieu of PERSONALIZATION.