running good notes on my private AppleID (=iCloud) and using it on my business Mac, too is today not possible. I'd even open to buy it twice, but I habe only 1 mobile device - so basically though I love good notes, I can't use it anymore.

Solution:
Allow to accept shared documents also from Mac App. This way I can still use it on my iPad and iPhone and notes I neet @work could simply be shared with my business AppleID.

This would provide a solution for many other feature requests such as
https://feedback.goodnotes.com/forums/191274-customer-suggestions-for-goodnotes/suggestions/40412074-sign-in-icloud-from-goodnotes-app-to-sync-personal
or the request to use other sharing options (dropbox, OneDrive etc.) as the background seems to be able to sync between different device and not be binded to a single AppleID.