I thought I should update you on this in case you are interested. We eventually came up with a python script that inserts html in between each letter and either changes the color to slightly-off-black-but-undetectably-so, or inserts formatting that doesn’t show up (e.g. <span>). This breaks the auto-translation plugin. It doesn’t prevent copying and pasting or image recognition, but we’ve deemed it good enough for our purposes for the time being.