ChaCha20-BLAKE2b VS libsodium-doc

I see what you mean; https://github.com/samuel-lucas6/ChaCha20-BLAKE2b would be considered borderline rolling your own. Especially when compared to https://github.com/FiloSottile/age/commit/2194f6962c8bb3bca8a55f313d5b9302596b593b as one solution or mitigation to the attack, and considering that it does not seem to a big problem for key based encryption (judging by the comments in that commit).

In the documentation that he sent me I could find some examples, which however used several messages, while for what I have to do I only need one which must be both the beginning and the end.

I have seen this.

If you look at the latest commits in libsodium-doc, then you'll see that Frank has now removed the padding fix suggestion, possibly due to me mentioning that in the Kryptor post (the timing matches anyway). His new recommendation is interesting, but he unfortunately doesn't cite any papers about the topic.

Interestingly, Frank just clarified a few things in some of the latest commits for the libsodium-doc repo. He is now saying to avoid using a password for encryption. I wonder what motivated him to do that.