There's a rumour that the BTM dev is actually Satoshi Nakamoto

I doubt that, but attempting to follow Satoshi's original vision of Bitcoin based on how it was presented in the original whitepaper and subsequent postings? Yes.
OK, so why do I say bitmark is the purest implementation of satoshi's paper. Three reasons.
1. Even from the first sentence Sashosi argues that micro trust is good enough for most transactions but presents a weakness that zero trust addresses. My interpretation of this is that, just as in real life, micro trust and zero trust are not binary options, but rather, work together. Bitmark does that.
2. Satoshi talks about reclaiming space from transactions. RESTful architecture is the most tried and tested way of doing this, we turn the web into our distributed database, giving massive storage, redundancy and bandwidth. In addition we still have a strong P2P network working together. This tech can be ported back to bitcoin and block explorers, creating a common standard.
3. Satoshi was working on a review and rating system before he left. That work was abandoned with him. But it's something that is at the core of marking and layered on top of the crypto currency bitmark. I think this is the direction Satoshi would have wanted his work to go.