In my use case I HAD to implement an 8 character password for my WiFi network. However, this was not accepted since Ziggo modems require you to have at least 10 characters as a password.
I fixed that :)
In the sourcecode of the WebUI it's easy to spot where the strength validation is happening. By simply disabling the return statements (Therefore just ignoring the errors) we can force the modem to accept the new password even though it does not meet the required limits.