What if you publish the form first directly from Infopath designer and then deploy the workflow. I haven't tried this approach. I guess the fields will be there due to the publish from designer and after the workflow is deployed, it might just use the columns because the form schema has not changed.

Running into the same problem right now. I have setup a step to upload the XML into the same Form Library once the WF has completed (such after approval or cancellation), but I saw that the properties within the form are not automatically promoted to the SharePoint library. Furthermore, the XML file does not automatically open within the browser. The system prompts me to download/save the XML file upon clicking on the item. Are you experiencing the same problem?

With regards to properties being promoted to SharePoint, a workaround I can think of is add a list item reference to the XML document item and then add step for updating the list item. I will then explicitly promote the fields from InfoPath. FYI that I am only using K2 for SharePoint designer.

I came to the same conclusion after a couple days trying to figure it out.

1.) Open the *.XSN template in Design mode in InfoPath

2.) Publish the form to the library you've created for K2 (To confirm go to the library and see the columns exposed)

3.) Redeploy the K2 project.

4.) Submit a new form (The existing forms will not show any data in the exposed columns)

5.) Create the views you want to filter on

**Edit**

*Note: You would have to add a Upload InfoPath Form Event in order for this to work.  This event will upload a copy of your form to the Library.

Property promotion became automatic as I made sure my filename had the .XML extension. This is configured in the Upload InfoPath form WF step :)

I was able to resolve my problem above by making sure i indicated .XML in the filename within the upload infopath form WF step :)