As I say in the first post, I've been able to extract ePub & PDF from LCP2.0.
I don't have any 2.5 to test on. But, from my reading of the specification, 2.0 - 2.9 are all the same scheme, they just have different encryption keys.
If you have a 2.5 book, I'd love to know if my method works for you -
https://shkspr.mobi/blog/2025/03/tow...rotected-epub/