Having the GUI resize based on your gui size would be helpful, because for me to read the book or to see the whole of the draconic chest I have to lower the gui size to see it.

Below are Normal GUI and Auto size as you can see when set to Auto I cannout navigate the book at all.

Yea... Thats more of a problem with vanilla. Vanilla just doesn't do well with guis larger then 256x256 It may be possible with a bit of work to make the manual gui scale properly by writing my own gui code. But for containers like the chest thats not really an option.