It would be nice to have support for Thaumcraft and Barrels mods. It's not a critical flaw though.

Crystal capacitor, as stated in the book, has a capacity of 100 Vis. If that can be tracked, that would be cool.

Barrels mod. It would be nice to see the number of items in the tooltip (as in mods WAILA + JABBA in 1.7.10). Although, there is an option in the config to display information from all sides of the barrel, but I think it might affect performance if there are a lot of barrels.

Good idea - will note it down for the next version, thanks! :)