I thought that was the case - but I emailed the club in the summer when I was debating what to do. They said that if you ever decide to get a ST again, you’d need to be a member again for a season before applying.
These things change though, so I’d probably ask the club. I would say that if you cancel your direct debit mid season, you’d most likely get black listed.
Its hard to get excited about things right now, and I’m also considering giving it up in the summer and switching to watching from home.