Yes, having more than one moonstone library is really helpful. 500 extra fragments a day really adds up over time. Oh how I wish Inno would put out an alternative for players who can only have one.
@Count Rupert Best workaround i have found is the trading stations that you can win in the spire, the PPs they produce can be fragged for a gain of 400 Spellfrags per day. I have been told by numerous players(
@Darielle) that i am going to be really sorry i frag those, but I have a BTG and all they will save me later is time so...
Another good trick, once you get into chapter 9 you get access to massive culture buildings in the build menu, you can build weeping willows(or whatever is larger in later chapters), teleport them into inventory and then frag them. It takes 17 hours to build and uses space, teleports, coins, and supplies but will get you 450 frags for each one(750 frags - 300 frags that the teleport spell is worth).