I'll admit this may not be the best solution to this problem but until WHMCS itself allows for stronger passwords, this at least solves the problem for Plesk.
I would have preferred to do an API call and find out what the server's Password Strength policy is prior to changing the password (ie: only set a strong password when the server policy is set to "Very Strong") however there appears to be no way to get password strength value via XML API.
I'll admit this may not be the best solution to this problem but until WHMCS itself allows for stronger passwords, this at least solves the problem for Plesk.
I would have preferred to do an API call and find out what the server's Password Strength policy is prior to changing the password (ie: only set a strong password when the server policy is set to "Very Strong") however there appears to be no way to get password strength value via XML API.
It solves these two WHMCS feature requests, but only for the Plesk module: https://requests.whmcs.com/topic/strong-password-for-newly-created-accounts-using-module https://requests.whmcs.com/topic/increase-auto-generated-password-strenght