Can a user get a second free trial on an in-channel subscription

Say we offer 1 month free on a monthly subscription and a user finishes the free trial and then cancels the subscription. If they start the same subscription product again, will they get a free trial for a second time, thereby enabling abuse of the free trial system to get indefinite free access? Or will the Roku In-App Payment process only give the free trial once per product on any Roku account?