I’m not sure how relevant that is with a program like this, that seems to barely have any formatting at all beyond bold and italics. I see you can change paragraph alignment per line, and there is something called a “Poetry Paragraph”, but neither of these things are beyond Markdown (particularly its more expanded forms as provided by MMD and Pandoc).
Even so, it has always been a premise, and all Markdown engines outside of web input (for security reasons) allow for the seamless interleaving of HTML and Markdown, specifically so you can do whatever you need, if “pure” Markdown doesn’t do it. For a file format, where a super clean file isn’t as necessary, that would be no problem, but again I don’t really see anything it is doing that would require a lot of manual HTML. For example, using Pandoc markup, it already has markup for verse:
| Line one
| Line two
| Line three
And I could also implement paragraph alignment like so:
::: Align-Right
Text of paragraph...
:::
This produces:
<div class="Align-Right">
<p>Text of paragraph...</p>
</div>
Well, it’s not too big of a deal what it uses to write to the disk, as I said above, I’m more interested in how I can write in a thing, and how I can export. For something as simple as this, HTML is fine really.
yWriter/Scrivener were always a bit of a combo of database and individual files.
I can’t speak to how yWriter works, but Scrivener uses zero database tech. The project consists of human readable XML and standard text file formats, and is specifically designed to be recoverable without extensive experience in computing or special software. The only exceptions are some volatiles that aren’t necessary for data reconstruction, like Mac PLIST files for state saving.