I've seen many puzzles based on Sudoku variants, as well as Mathdoku/KenKen, but haven't seen any in our area based on this game.
With a bit of research, you should be able to figure out what the game is, the title might clue you in. For the first stage of the puzzle, you can ignore the gray capital letters, or perhaps you can use them somehow... Once you are successful in solving the puzzle, you can find the cache coordinates at
North: B(N+K+J) P(H+J) . J (N+L+M) (P*D)
West: ADG (E-F)H . (A-C)(N-M)(B+E+G)
You can validate your puzzle solution with certitude.
Happy caching!
Congrats to raggedblossm for her first-ever FTF!