Right now, the only way for a member to update their billing details (credit card info) is to click on the text link supplied through the "Subscriptions" SmartTag Form.
This text lockup "Update Billing Details | Cancel" is problematic on mobile devices, especially when over 50% of my members are mobile-only, so my support team has to do a lot of hand-holding getting members' credit card info updated manually. Even when using css to style these elements, it's difficult to target the | character with css to hide it or get it out of the way.
A SmartTag that provides an easy button for clients to update their credit card info is crucial to provide an mobile-friendly solution for my members.
Thank you for this suggestion! This feature request or some aspect of the functionality suggested is currently being reviewed for possible inclusion in a future update. If there is additional information, this post will be updated to reflect it.