Add markdown but hide it

Hi, 

so I would like to be able to be ready for whenever I would export what I do in Workflowy into a book.

From what I understand from the blog, to avoid spending time on styling, one could add some markdown directly. It would mean that when I write a title, I type # before (or use PhraseExpress)

I'm not crazy about the idea because it's messing with WF clarity and fluidity.

I thought about using the underlining, bold etc shortcuts to style things. So using css with Stylish I now have beautiful titles, fonts etc. My document looks nice. But of course this can't be exported. When I export, it's back to text.

I then tried to use css to add directly # when content is underlined ( <u>), using the ::before trick. But it doesn't really add the # in the content, so it disappears when exporting.

I know that WF team is not planning to use Markdown (and this is not the ask). But is there a workaround for preparing a file to be exported some day, keeping the hierarchy and logic of the doc?

It could be a custom script that adds the # to all <u> elements the day I export, but this is where my javascript knowledge ends.