Not a single lossless compression technique I’m aware of starts of in lossy compression.
They have different goals and utilize completely different techniques.
At most lossy techniques leverage lossless techniques (eg to compress non-perceptual binary headers) not the other way round.
Here's the submission that won the Hutter Prize in 2021: https://github.com/amargaritov/starlit It uses a LSTM to predict the next token lossily, then uses https://en.wikipedia.org/wiki/Arithmetic_coding to convert that to lossless compression. Lossless compression can definitely leverage a lossy compressor, such as via arithmetic coding. Also see: https://en.wikipedia.org/wiki/Context-adaptive_binary_arithm... which has a simple "Example" section - imagine if the top prediction made by your neural network was correct, you emit "0", if the 2nd was correct, you emit "10", if the 3rd, "110", if the 4th, "1110". As you can see, this is lossless, but the fundamental prediction is lossy, and the better that prediction is, the better the compression. (In actuality, you wouldn't waste your 1 bits like this, you'd use arithmetic coding instead).
Why wouldn't it be? You're not actually hosting a tracker in this case, only looking at incoming connections. And even if you do run a tracker, hard to make the case that the tracker itself is illega. Hosting something like opentrackr is like hosting a search engine, how they respond to legal takedown requests is where the crux is at, and whatever infra sits around the tracker, so police and courts can see/assume the intent. But trackers are pretty stupid coordination server software, would be crazy if they became illegal.
"I then started the tracker. After about an hour, it peaked at about 1.7 million distinct torrents across 3.1 million peers!"