James,
Given your stated goal of creating an audit trail, utilizing the LOG might be your best bet. HEO already logs what actions occur and are committed and, if you're using outlines to drive your iForms, you're already getting "iForm level" tracking of what's ordered and how. The piece that I think you're missing is *before* the order is successfully placed. ("Did they place the order via the iForm, but remove it before committing?" etc). You can get some of this by logging (1) the submitted state of form elements and/or (2) the entire orderstring.
A word of caution, however - while this will give you more information about how the iForm placed orders, it will not capture certain edge cases. For instance, if the user is correct and the iForm is not working correctly, then it will be hard or impossible to prove. Consider the example where a med is dosed based on a drop-down field, but there is a typo on the form where it displays 15 mg, but sends 30 mg to the VGR.
<option value="30">15 mg</option>
It will appear in the logs that the user chose 30 mg even though they may have chosen 15. Now, if this medication is given at the wrong dosage in January, the typo is discovered and fixed in February, but an audit is performed in June, it may be next to impossible to trace the medication error to the typo unless your documentation is superb.
Just a word to the wise. Best of luck,
Scott Morris