Hi Fast Eddie,
Is this related to your other post regarding taxes? Method will keep the same data as QuickBooks, so if a Customer/Item are marked as taxable in QBO then make sure you perform a Full Sync then refresh your screen in Method and check again.
If you want to change the default value then you would need make a copy of the ItemInventory screen (remember to replace tab links), edit it, then edit the Tax field and set the default value to Tax. Publish and save the screen. You would then want to do the same for the CRM_EditCustomer and CRM_NewCustomer screens.
- Ashur