CWP imposes the 8 character limitation, just as cPanel used to (and cPanel is something of the spiritual father/reference platform for CWP). But the command line useradd utility can do up to 32 characters. I haven't tested to see if you do an end-run around CWP and it would respect the longer user name. But my suspicion is it would truncated it to 8 char because of the need for longer permutations for MySQL user + DB names: username_dbname. Perhaps this will be something they fix when they start offering EL9 support later this year or next year. AlmaLinux 9, here we come!