I wonder if these 2 concepts are worth "unpacking". Do they not encompass 2 different "ideas"- I had raised it before with Els (before we had the forum!).
I think that "scripts" are an interesting and worthwhile "connection" - just where can you go to see the different writing systems from around the world? This is what the "writing" connection was orignally meant to be I believe. As such only sites which are significant in that sense should be included (again the defnintion needs "beefing up") - the text should highlight the script concerned. Byblos, Jelling, Bisotun (et al) are certainly in this category
Libraries are collections of "books" (in the widest sense) - so Haeinsa Temple with its wood blocks is a "Library". There may indeed be some "libraries" which are also significant because they are a repository of an early script.
By the way I would add Mogao to "Early Mechanical printing" - The Diamond Sutra which came from there may be in the British Museum but it is the earliest example of mechanical printing - again the text could explain the link