I have implemented 3 different subscription plans. The first is a paid trial that lasts 10 days, the two others are types of monthly plans (again paid). All three are available to select when the user sign ups.
However currently anyone on the two non-trial plans can move to the trial at any time. This seems counterintuitive. Instead I want the trial to only be available at sign up and not be in the list of subscriptions a user can move to once they have signed up.
How can I implement such logic in Membership?