Komodo NNUE

In last week's post on chess engines, Stockfish Wins TCEC Cup 7; CCC GPUs Back, I mentioned a CCC event called 'Mystery Engine Debut and Tuning'. This led to the question:-

What was the 'Mystery Engine'? We may never know, although some sources are certain it was 'Komodo NNUE'.

When I wrote that, I reckoned that 'We may never know' was likely to be short lived. Indeed, a few days after the post we learned, Komodo Releases Powerful New 'Dragon' Chess Engine (chess.com; by Sam Copeland). It started,

The Komodo team has released Komodo 14.1 and a new chess engine dubbed "Dragon." Dragon adds powerful NNUE (Efficiently Updatable Neural Networks) technology to the successful Komodo engine.

After a short explanation of the NNUE technology...

NNUE engines have proven to be a major advancement in chess engine technology, allowing traditional tactically powerful "brute force" engines to incorporate the deeper positional understanding evinced by neural network engines such as AlphaZero and Leela Chess Zero.

...the article confirmed that Komodo NNUE was the mystery engine:-

In a debut and tuning tournament in the Chess.com Computer Chess Championship, Dragon finished fourth behind Stockfish 12, Leelenstein and Leela Chess Zero.

That sentence was followed by the crosstable for the 'Mystery Engine' tournament. Along with some marketing hype for the Komodo engine -- multiple 'World Champion' (i.e. ICGA) titles -- the article included a link to a previous article by the same author about Stockfish NNUE, Stockfish Absorbs NNUE, Claims 100 Elo Point Improvement (chess.com; August 2020), which I don't think I had seen before.