By not following the spec Alby is causing all other clients to break. Because Alby is the biggest provider everybody will assume that whatever Alby does is the spec and others will have to either follow or die. You might as well call it the AlbyLN standard. If that is not centralization I don't know what is.
You can do it, no one is going to stop you. But you can't also keep saying it's an open standard.