The plugin execution order is as follows:
PluginA::beforeDispatch()
PluginB::beforeDispatch()
PluginA::aroundDispatch()
The code in the around plugin
PluginB::afterDispatch()
PluginA::afterDispatch()
The aroundDispatch() method is executed in a separate scope, so the code in the around plugin will be executed after the beforeDispatch() methods of both plugins, but before the afterDispatch() methods of both plugins.
Here is a diagram that shows the plugin execution order:
PluginA
beforeDispatch()
aroundDispatch()
afterDispatch()
PluginB
beforeDispatch()
afterDispatch()

To display the "file upload" field and process the actual CSV import, the following two requirements must be met:
The developer must create a new system configuration setting that specifies the path to the CSV file.
The developer must create a new controller action that handles the file upload and import process.
The system.xml file is used to define system configuration settings. The following XML snippet shows how to define a new system configuration setting for the CSV file path:
XML
<config>
<system>
<config>
<shipment_fees_csv_path>/path/to/csv/file</shipment_fees_csv_path>
</config>
</system>
</config>
The Controller\Adminhtml\ShipmentFees controller class is used to handle the file upload and import process. The following code shows how to create a new controller action that handles the file upload and import process:
PHP
public function uploadAction()
{
$file = $this->getRequest()->getFile('shipment_fees_csv_file');
if ($file->isUploaded()) {
$importer = new ShipmentFeesImporter();
$importer->import($file);
}
return $this->redirect('adminhtml/system_config/edit/section/shipment_fees');
}

The developer can use the canInvoice method of the order object to check if the order can be invoiced or not. This method returns true if the order has a state of new, processing, or payment review and has not been fully invoiced yet. The developer can use this method in a conditional statement to send the order ID to the ERP system only if the order can be invoiced. Verified Reference: [Magento 2.4 DevDocs] [Magento Stack Exchange]

According to the Develop data and schema patches guide for Magento 2 developers, data patches can also implement PatchRevertabieinterface to provide rollback functionality for their changes. The revert() method contains the instructions to undo the data modifications made by the patch. To ensure that the product attribute is removed when the module is uninstalled, the developer should make the data patch implement PatchRevertabieinterface and implement the revert method to remove the product attribute using EavSetupFactory or AttributeRepositoryInterface. Verified Reference: https://devdocs.magento.com/guides/v2.3/extension-dev-guide/declarative-schema/data-patches.html

According to the Plugins (Interceptors) guide for Magento 2 developers, plugins are class methods that modify the behavior of public class methods by intercepting them and running code before, after, or around them. However, some classes in Magento 2 implement the NoninterceptableInterface interface, which prevents plugins from being generated for them. The Magento\Framework\App\cache\Proxy class is one of them, as it extends from Magento\Framework\ObjectManager\NoninterceptableInterface. Therefore, the plugin is not executing as expected because the target class implements NoninterceptableInterface. Verified Reference: https://devdocs.magento.com/guides/v2.3/extension-dev-guide/plugins.html