These are 2 suggestions we found while implementingmake:auth for the new system (symfony/maker-bundle#736):

Impact on a custom login form authenticator (as generated by the new maker):

• Automatically addPasswordUpgradeBadge if there is a user password with valid password credentials.

   // ... return new Passport(     new UserBadge($userIdentifier),     new PasswordCredentials($password),     [-        new PasswordUpgradeBadge($password),         new CsrfTokenBadge('authenticate', $csrf),     ] )

  Note that this does not automatically migrate all passwords: it still relies onPasswordUpgraderInterface to be implemented on the user loader/provider.
• Add default implementation ofAbstractFormLoginAuthenticator::support()

  - public function supports(Request $request): ?bool-  {-      return self::LOGIN_ROUTE === $request->attributes->get('_route')-          && $request->isMethod('POST');- }

cc@weaverryan@jrushlow