It appears the plugin is working normally, very happy with the plugin. Although backing up is taking a lot longer these days because of a large amount of json files located in the data/Backpacks folder. I am wondering if I can remove these files or some of these files? It is normal to have so many (and growing)?
It just says OwnerID and size, very small amount of data in each file. Although about dozen or so are almost 10KB, all the others are 1KB

They should be one file for every player that has ever joined your server that had access to backpack, and the contents of each of those backpacks. That's why I changed it to a VIP only perk, too many files ........  

You can always use these options to reduce file size,

"Clear Backpacks on Map-Wipe (true/false)": true,
  "Only Save Backpacks on Server-Save (true/false)": false,​