The \Magento\Tax\Model\Layout\DepersonalizePlugin::beforeGenerateXml() method can be simplified by returning void instead of an array

This can be simplified to:

/**
 * Before generate Xml
 *
 * @param \Magento\Framework\View\LayoutInterface $subject
 * @return void
 */
public function beforeGenerateXml(\Magento\Framework\View\LayoutInterface $subject)
{
	if ($this->depersonalizeChecker->checkIfDepersonalize($subject)) {
		$this->defaultTaxBillingAddress = $this->customerSession->getDefaultTaxBillingAddress();
		$this->defaultTaxShippingAddress = $this->customerSession->getDefaultTaxShippingAddress();
		$this->customerTaxClassId = $this->customerSession->getCustomerTaxClassId();
	}
}

A trick: a «before» plugin can return nothing if it needs not modify any argument