Firebird users with the same names but different passwords

Firebird Friday Joke #7 is devoted to the often confusion of newbies in Firebird 3: the ability to have users with the same names but different passwords in different user managers.
For example, we can create one user with Srp (as default plugin), and another with Legacy_UserManager:

SQL> CREATE USER newuser PASSWORD '12345';
SQL> CREATE USER newuser PASSWORD '67890' using plugin Legacy_UserManager;
SQL> exit;

and then login to the database with the same usernames, but different passwords

E:\testFB\Firebird_3_0>isql  localhost/3058:d:\o30copy.fdb  -user newuser -pass 12345
Database: localhost/3058:d:\o30copy.fdb, User: NEWUSER
SQL> exit;

E:\testFB\Firebird_3_0>isql  localhost/3058:d:\o30copy.fdb  -user newuser -pass 67890
Database: localhost/3058:d:\o30copy.fdb, User: NEWUSER
SQL> exit;

We can identify these users:
SQL> select SEC$USER_NAME, SEC$PLUGIN from sec$users;

SEC$USER_NAME                   SEC$PLUGIN
=============================== ===============================
NEWUSER                         Srp
NEWUSER                         Legacy_UserManager

But we cannot tell which user has what password :)