I haven't seen any other paper insert design to be honest, but it would be very hard to protect the idea - however this post on the blockchain can be a testement that I came up with it first.

The water resistance idea is awesome ! This definitely should be included . I will think about how to implement it - maybe a rubberflap is the way- it should be the most simple and best - awesome suggestion - thanks buddy ! And also thanks for pointing out the misspells- I appreciate it :)