Passwords are limited with Regex in Flexi-Auth

Hello,

In Flexi-Auth, i noticed passwords are limited with the following regex ( only accepts alphanumeric and . , - _ )

PHP Code:

$config['security']['valid_password_chars'] = '\.\,\-_ a-z0-9'; 


I've read it is bad to limit password characters, so i changed it to the following:

PHP Code:

$config['security']['valid_password_chars'] = '\!\@\#\$\%\^\&\*\(\)\+\=\~\<\>\?\:\[\]\{\}\|\.\,\-_ a-z0-9'; 


Now it allows almost all standard special chars except: ' " `

1. Is there a reason Flexi-Auth have this limit?
   
2. Is what i'm doing wrong? i need to know it won't cause any issues
   

Any help is appreciated