I think it's a great resource to have, especially if you plan on adding new types in your game or changing up the type chart like I am. I only have one request that could make it a lot better when given access to the player.
I noticed that it works based on your region, so would it be possible if you could add a setting in the plugin where you can only see the species that you have encountered? Like say you have Bulbasaur but you do not have Caterpie, so the plugin would not show Caterpie in the list of pokemon for the Species Type Matchup List if you understand what I mean. Still a great resource even if not given to the player.