After clicking export in Funnel, the lead should be sent to TASS and held in a "processing area" under the tab Enrolment Information > Online Enrolment Applications.

While a students record is in this "processing area" you will be able to do as many exports and updates to their information as you like from Funnel:

However, the leads documents will not fill their UD (User Defined) areas unless you click the "Review" option next to the leads name.

This should open up a screen with their details and if there are no errors, there will be a button on the bottom right labelled "Add Enrolment". Once you've clicked this button, you'll need to go back to Funnel and click export to fill the leads UD (User Defined) areas with documents.