Hi, thanks for interested in our plugin. There isn’t option to control size of images resized it. The plugin have got a tool to auto detect images in your posts which are not in good size (For example the image’s size is 600px x 500px, but in the post it display in 300px x 250px), then it report wrong image size and ask do optimize them.
About image resized quality, we used php function imagejpeg with default quality 75%, you can increase it by modify the line 505 in the file inc\class.image-helper.php
case ‘jpg’: imagejpeg($new, $destination);
to
case ‘jpg’: imagejpeg($new, $destination,99);
Regards