Thank you. This is encouraging to hear from a potential user. There may be a middle ground where new features are sold separately (specially feature requests). Having said that, everything you get today with v1 will remain covered by what you paid for the app. No rug-pulling ever to force folks into a subscription.
It is how Beorg does it - they have a subscription covering everything, but users can also buy singe features. However, I imagine that at some point the coding will get quite complex - developer has to build a couple of feature toggles and ensure that they work well in every imaginable combination.