My PRO subscription recently expired and the first I knew was when it wouldn’t let me access my own trees because they are private which is only allowed on a PRO subscription. It took me a moment or two to work out what was going on.
I didn’t receive an email to let me know my subscription was about to expire so that I could proactively renew it.
Could you build in one or more subscription reminders, not to nag, but simply to inform??