Defining a flag that should not be burned is hard to do intelligently.
In the mid-1980s I was at a July 4th parade in Atlanta with a lot of nice U.S. flags in the parade, but someone was handing out free tiny flags that deserved burning. They had a big "Made in China" label, and the star field and stripes were badly misprinted and out of alignment.
That was about the time the whole fuss about flag burning started, and I remember thinking that no one understood that some flags need burning.
Taking any symbols too seriously is stupid and a waste of time and effort.
Why would you assume that books are text only? I have a number of PDFs of coffee table picture books that are 256MB to 512MB or more in size. I have PDFs of lots of 19th century books with a lot of photos and drawings embedded. And I have one PDF 1.15GB in size with over 14,000 scanned articles in it, from 1870-1920. 256GB isn't an excessive amount of storage for serious book collections.