Values from read-only fields on your web form are not being submitted back to WorkflowGen even if you have the proper OUT parameters and process data set up.
This is not an issue related to WorkflowGen, nor is it a bug within your browser, but in fact a W3C standard regarding form submission.
WorkflowGen.My has no control over this behavior since the fields are not considered “Successful” and therefore not submitted back to WorkflowGen.
Since this issue has not been identified as a bug but in fact as a W3C standard, there is no workaround per se, but there are ways of dealing with the issue properly. For example, one proposed solution is to create a hidden input field on your form that will contain the value to submit back to WorkflowGen. This hidden field will need to be populated with the proper value prior to submitting the form.
<input ID="MyHiddenField" runat="server" Type="hidden" Text=""/>
Note: In previous versions of Internet Explorer and Firefox, read-only controls may have been submitted during a form submission and therefore considered as “Successful” controls by the browser, but it was likely due to the browser version not being compliant with the W3C standards.