Here are some questions and answers to help you decide whether the text proposal file would be useful for you:
The text proposal syntax has been added to the Phase II Proposal Instructions for reference. It is set apart in brown text. For an example look in section 6.1 for the "Additional Rules and Conventions for the Text Proposal File".
One potentially confusing difference between the text proposal structure and the APT proposal structure is the way exposure groups are represented (e.g. parallels,patterns and non-interruptible exposure sequences).
To import the .prop file back into APT click on File/Import/Import Text proposal. See the section below for how to deal with errors found in your .prop during import. If the import goes well you can reprocess the proposal and File/Save to a new an improved .apt file.
As with the previous example you will want to first save and close your original version of the proposal before importing your generated .prop file. And you will likely go through a few iterations to get rid of syntax errors (see below).
Note that in some cases you may have entered a value for something that should not have a value or the field has a required value and you have specified something different (the pattern specification fields are an example). APT will report the error with a red X, but you will not be able to fix it in APT because the APT Form Editor locks out fields you should not be changing. You will have to fix this type of problem in the .prop file and reimport.