Hi Kurt,
There actually is no way in Method to change the ContactType value, this is a field in QuickBooks that we can read but not modify/edit in Method. If this is for QuickBooks Desktop version, I can tell you that we sync with the main QuickBooks contact, which shows up as the "Primary Contact" in QuickBooks, which when synced to Method will display as "Contact". We also sync with a secondary contact NAME from QuickBooks, however this can only be done by adding the Contact first in QuickBooks, and making sure you use the "Secondary Contact" type. If you do this, your secondary contact NAME will get synced with Method, however in Method this contact will display as "AltContact", instead of the "Secondary Contact", as it shows in QuickBooks. If you do it this way, after adding your secondary contact in Method, you should be able to fill out their other details from the Edit Contact screen in Method, just keep in mind none of this additional information will get synced back to QuickBooks.
Please give this a try and let me know if this workaround solution helps.
-Ben