Override the Maya Drag and Drop Behavior for File Open/Import

performFileDropAction.mel

//  Randall Hess randall.hess@gmail.com
//  Instructions: Copy this file over your local maya version to override the default behavior
//  Maya 2022 and Higher
//  Additional: You can also build and load this as a module and not overwrite the local maya file.

//  Location: C:\Program Files\Autodesk\MayaXX\scripts\others\performFileDropAction.mel


global proc int
performFileDropAction (string $theFile)
{
	string $msg = "Would you like to Import, Open or Reference the file?";	
	string $import = "Import";
	string $open = "Open";
	string $reference = "Reference";
	string $cancel = "Cancel";
	string $response = `confirmDialog -message $msg -button $import -button $open -button $reference -button $cancel -defaultButton $cancel`;
	if ($response == $cancel)
	{
		return(1);
	} 
	else if ($response == $open) 
	{		
		global string $gOperationMode;
		string $save_gOperationMode = $gOperationMode;
		$gOperationMode = "Open";
		int $result = performFileAction ($theFile, 1, "");
		$gOperationMode = $save_gOperationMode;
		return ($result);	
   	}
	else if ($response == $import)
	{
		file -import -namespace (basenameEx($theFile)) $theFile ;
		return(1);
	}
	else if ($response == $reference)
	{
		file -reference -namespace (basenameEx($theFile)) $theFile ;
		return(1);
	}

}

Updated to reflect the latest Maya versions for now. Thanks Nate!