About your first request, do you wish the title to be updated every time the user selects a different font-family or font-size in the menu? The problem with matching the title’s font with the font inside the ebook, is that the ebook can have its own custom fonts (possibly more than one) with various sizes.
Or do you wish that the title matches the font of your page outside the viewer?
I might add a couple of css variables like --simebv-ui-font-family (cfr. the readme) to allow the customisation of the title’s font (the result would be static, though).
Regarding your second request, I’m considering it. I’ll do some experimentation.
Good questions. By default, the header font should match the body text font. I understand that the ebook could have multiple fonts. In that case, just pick one used in the body of the text. I recognize that can be tricky, since the first words in the story may be a preamble in a different font from the body text. But you have to choose something.
To cover cases where that is the wrong choice, you could add options to set the header font.
I don’t know what you mean by the “font of your page outside the viewer.” Do you mean the surrounding web page? If so, I would say you should ignore that font and focus only on the ebook’s default font.
I did recently see a guide on creating EPUB books called “The Complete Guide to Creating EPUB-Ready Documents for eBooks” by Paul Hoke. He advises against using headers or footers in an ebook, as the standard doesn’t allow them and they can cause problems. But since you control the plugin and already have a header option, I figure you can do whatever you want.
Right now, my workaround is to set the title to a blank character so nothing shows at the top of the page.