We just started using the ChargeBee platform and the first step is setting up the current state of our business.
In order to that (regarding the subscriptions), we had to use the Import Subscription feature in order to be able to add subscriptions activated in the past that are currently active (a regular case when starting to use a new system). You can find the issue here: https://support.chargebee.com/support/tickets/116119
I believe this could be a straight forward procedure from the adding subscription UI, without having to use a CSV import in order to achieve this.
Thank you for your suggestion.
We'll discuss this with our team and see if we can take it up as a feature request.