RED update thoughts and feedback

Are you talking about the old 4 options because I can get the new Mastery Book 20 by trading in Guardian 20 or Guardian 30 for example.

And I can trade in Advanced Blessing 30 considering that its level has decreased from 30 to 20.

I'm talking about the first option (the one that "disappears"). If you have an eligible book in your inventory, you'll get the new MB20 or MB30, depending on your choice and not the level of the eligible book.

No idea if that's how the specific book options work, though.