Multiple duplicate apps pointing at different tables

I have an app designed to present information to the user from google sheets.

We have lots of different client tables with unique data but the same column format. I cannot merge tables for security reasons (i.e. I can’t make one master table then partition within AppSheet). Currently I am copying the app, renaming it and pointing it to a different table in google sheets as a way of creating new apps for different clients. This clearly isn’t a scalable solution as if i want to make changes to the app, they all must be done separately.

Is there some way of making a ‘Master’ app, where the ‘daughter’ apps will inherit any changes to the master?

Or is there some way of the user selecting which table the app should point to, from an option of ‘allowed’ tables as defined for each user by the administrator?

Any other advice on other ways to tackle this issue in a scalable manner would also be much appreciated.

Worth reading the app scaling from here.