DB user accounts

Hi, for our project I’m trying to replace the flat-file accounts by user accounts stored in a database. I thought that I could simply override the functions in User and Users that read the credentials and available users by my own DB queries. So, I thought that a User[s] plugin would be the way to go, but I cannot overwrite functions the default function :disappointed: as written in here:

So, my next thought was to write my own DBUsersApp class and inherit from the App class but inject my own AppUsers extension that has a custom AppUsers::users() function. But I don’t see, how I can tell Kirby to use my own DBUsersApp class for $kirby and kirby() and anywhere else the App class is used.

Could somebody help me out here?