Different Default Invoice Selections & Text Based on Invoice Type

When I prepare service dispatch invoices, the same options are selected and the same text appears when I select RTM as the invoice type as which appear when I select T&M or Contract as the invoice type. It would be great if all of the defaults (e.g., description text, attachment of inspection report) were specific to the invoice types. For example, it would be great if I could have the inspection report automatically attached to RTM invoices, but not to the other invoices.