How to disable "autocorrect/autofill" on SOAP requests

• Using ReadyAPI to do a data driven test against a SOAP API.
• On each iteration, putting XML in the values for a properties test step. This is so that we can have some tests with missing elements, or other structural options.
• Using a placeholder in the SOAP request to grab those property values (see image).
• Whenever I save the project, ReadyAPI goes into my request, sees missing elements (because the placeholder puts them there during runtime) and "helps" me by shoving empty element tags in there for schema compliance.
• Next time I run the test, it fails because of extra tags... I have to remember to go into the request and delete the extra tags. One day I may forget and raise an embarrassing defect.

Main Question: Is there a way to disable this "help" that keeps making things more complicated?

(please support negative test cases - they're critical for robust testing)

Thanks