This system does not seem fair, at least as it appears on paper.
是否可以理解为：This system does not seem fair, at least as it appears on paper （that this system does not seem fair）.其中as=that this system does not seem fair.

不过又觉得这么理解不妥，因为按照某种说法（曹老师曾经讲过），as it appears……中的形式主语it不能单独出现，必须和逻辑主语（that this system does not seem fair）同时省略。（也可能是我对曹老师的讲解理解不到位，在这里进行了错误的类推。曹老师的讲解原文：例如：The difficulties are even greater than (it) appears (that they are.) at first sight.……如果省略that从句，形式主语it必须同时省略。）

非常期盼老师的指点。