I can understand your vision, here is ours:
When you purchase AcyMailing Enterprise, you purchase the possibility to use it automatically (and some extra features).
So that's a kind of yearly subscription to use the service.
At the end of the year, your subscription is expired and AcyMailing can't be used automatically anymore.
If you allow people to use their own cron job then why would they subscribe again?
That's the same for every software. You pay for some extra features / services then if your subscription expires these features are not available anymore.
If your Spotify subscription is expired, you don't have any way to listen to unlimited music without ads and there is no way to do something on our end to access the premium features for free.
Same for Netflix and many other platforms.
Purchasing a car or a house is a totally different thing as you pay for the car itself, not for a daily service.
What do you think about this?