As you already know besides "never saving" or just turning off the TK browser extension, there is no current way to turn off the automatic login save, but certainly it is a great suggestion to convey to our development team.
I too think this is a required feature to have. It can get quite annoying when True Key tries to save every password screen it encountered.
The Password Generator is a great way to create strong passwords to protect your accounts but you may prefer to create your own passwords or pass phrases. To turn off the Generator: Click on the Generator icon within your True Key app. Next to 'Automatically generate passwords in forms', click on the toggle switch to turn it to OFF.