I don't want to be rude, but after checking your code I can say that what you did is most definitely not the same thing as the compact Merkle multiproof idea..
Here's a test case illustrating such a proof: https://gitlab.com/NebulousLabs/merkletree/-/blob/bae5b54749...
During the upcoming days I'll add to the paper that you were the first to propose this algorithm.