You can watch the full Season 23, including the Coming Out special and highlights (M4B), on official platforms:

Here is the legal reality: The M4B files floating around the internet are generally fan-made conversions. Dedicated fans rip the audio from the TV broadcasts or ITVX streams, edit out the visual dead spots (long shots of trees, extended silences), and then encode the audio into the M4B container with proper chapters.

A great M4B file for Season 23 is useless without good chapter markers. Here is how a premium fan-made M4B is usually structured: