Actually I do not disable WordPress auto-resizing, perhaps I was using wrong words, sorry English is not my native language.
WordPress will automatically generate 3 thumbnails for large images uploaded (small: 150×150, medium: 300×300, large: 640×640). It’s good for most cases. But not for me, I will automatically resize and upload the smaller size if I need. Why? Using File Manager (cPanel) I saw there were too many images being auto generated by WordPress in the upload folder, most of them were just taking space because I never use it.
On most cases I only use thumbnail 150×150 and full size. That’s why I put 10000×10000 for the medium and large size to prevent WordPress to generate thumbnails for medium and large sizes. So I do not disable auto-resizing but just prevent the generation of the 2 sizes. And I can see the 150×150 thumbnails are being generated there, it’s mean the auto resizing is still working.
I did researches and tested many similar plugins. I’m sure your plugin has good future. Good work friend! Unfortunately my half hour testing showed too many issue need to be fix to work properly.