[Doitsu]

Originally Posted by AlanHK

Also, this: https://github.com/JayPanoz/Soma/wik...to-embed-fonts
says you can do this with just a change to the OPF. Is that correct?

AFAIK, it should be sufficient to use the .opf entries that are mentioned in the linked Github post.
However, I don't know when Apple introduced these metadata entries. I.e., it might be necessary to include com.apple.ibooks.display-options.xml for older iBooks versions.
For more information, also see this post.