With this question I want to go further and to exactly know if it's possible to override:
so far I've experienced some complications performing this override, I had to override also PlaceOrderDefaulr, PlaceOrderFactory and PlaceOrderInferface
I've added preferences tags in ../etc/di.xml of my module to include above mentioned classes, but now the error prompted is:
Fatal error: Uncaught TypeError: Argument 2 passed to Magento\Multishipping\Model\Checkout\Type\Multishipping\State::__construct() must be an instance of Magento\Multishipping\Model\Checkout\Type\Multishipping, instance of Vendor\MyModule\Model\Checkout\Type\Multishipping given, called in /var/www/html/vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php on line 111
I've cleared /generated folder and also /var/cache, view_preprocessed, page_cache, session/
and the error is still the same.. as a second parameter in constructor the follwing is called:
Then used to retrieve logged-in customer information to get addresses, etc.
Any ideas? will be appreciated.