piwan

Answering myself.

After looking into the code, obviously this is not supported.
Are you planning such feature in future?
Just in case anyone wanders how to get it right now: I have temporarily obtained it by slightly modifying plugin code as below.

1. Storing all the session checks in separate table (index key being important here). Before, only one session check was allowed to be stored (in Users table)

CREATE TABLE xxx_EWD_FEUP_Users_Sessions (
  User_ID mediumint(9) NOT NULL DEFAULT '0',
  User_Sessioncheck varchar(255) DEFAULT NULL,
  UNIQUE KEY index (User_ID,User_Sessioncheck)
)

2. Updating Confirm_Login() function in Functions/Process_Front_End_Forms.php file, to save session checks in this newly created table instead in Users table

3. Updating CheckLoginCookie() function in Functions/CheckLoginCookie.php file, to check all the rows in this new table, if there is any session check in them.

Do you see any pitfalls of such modifications?
Best regards