Yeah which frankly gets annoying fast when dealing with multiple users. As you need to remember the UIDs of all the users and match them potentially on all systems.
A solution to this problem is using active directory or if it is only for Linux devices FreeIPA. Which isn’t as bad as it sounds. It even simplifies it if you ask me. More centralized management. It is a onetime effort to setup correctly then just keeping it in check.
I actually installed the app on top of a Eversolo DMP-A6 Works fairly well. although the UI is a bit small on it.