Interesting points. Building on your "bits of freedom" point, given they are doing this to comply with the EU AI Act, it's also possible that the algorithm is quite weak. And they could play all kinds of games, such as embed it in the session data overall, not just the output (I don't know any details, so just guessing).
And thinking out loud, they could be really horrible and embed by using unicode characters instead of ascii, which would give a lot of flexibility, but would make the result almost unusable (but easy to defeat).
And thinking out loud, they could be really horrible and embed by using unicode characters instead of ascii, which would give a lot of flexibility, but would make the result almost unusable (but easy to defeat).