This has me thinking of a mitigation technique and that is: deliberately slow down the Internet connection of your company/vendor/whatever such that large volumes of data take an age to grab. Just like setting your language to Russian on the OS to stop ransomware from running (an old trick). Fast connections are a liability in some cases and in malware ridden machines it just makes exfiltration easier. Not saying damage won’t be done, but in some cases deliberately throttling connection speed is a win.