If it is a real anamorphic lens I assume you will need to digitally stretch the resulting images horizontally. In my admittedly brief skim of your link I saw no mention of it.

Edit: found the same lens on Amazon, read some reviews. Yep, it's the real glass. Images need to be stretched to 'normalize". One reviewer: "Yes you’ll need the moment app to desqueeze the image." (Of course can probably do the same in any image editing app.)