Carry over production subscriptions to Testflight beta build?

Hello,

I have a specific use case in mind, that I want to implement in my app. I would highly appreciate it if you share with me your thoughts on it.

Let's say we have a production app with N features. Think about those features as different tasks they can help you perform.
The app has 3 different recurring subscriptions with different length periods. Let's say that a user can use all those N features only if he has an active subscription of any kind. If there's no subscription, only a subset of those N features can be used. Freemium business model.

We also have a group of X people who have installed the Testflight beta build of the app. Users join the app via a public link, so it's open beta testing. Users reside in beta as long as they want.
In beta, the app offers N production features + M features which are being beta tested and are due to be released in production.

My idea is to ask the beta users to have an active subscription in order to use the N production features in beta + the other M features who are totally free in beta (they will become paid after they get released in production).
Yes, I am aware of Apple wanting all purchases in beta to be free, but in reality I want my beta users to have an active production subscription made in the production app, which they can use after installing the beta.
If I do not choose this approach, I'll have to limit the beta period or find some other solution.
Just wanted to ask if somebody has thought about this?
All I know from my proof-of-concept testing is that even if a user in production has active subscription, if they install the beta via testflight, the App receipt does not contain any data for the active production subscription, hence I cannot verify that the user can use the N production features in beta.
And again, all this is necessary because my beta is not time limited.

Thanks in advance!