> Visual is part of the package for advertisement, not for scientific/important stuff production
That's where my experience differs.
Knowledge is fractal in nature; I can add more details to a paper ad infinitum. Seeing how big the rendered paragraph or section will be is, to me, a crucial hint that it might be time to stop.
Seeing how far away two mutually dependent concepts appear in the finished product (when you a know a reader will likely have to jump back and forth between them) may also influence my writing. If they're getting too far apart I might have to introduce A, then B, then more details on each, to keep the introductions close together.
Deciding whether certain details are better communicated in the figure, the figure caption, or the main text also depends on the layout.
Knowing how large the section/subsections headings are may influence my choice to use less of them, and group some items into the same section, because I find excessive division into subsections makes things harder to read.
And I'll admit this is weird, but somehow this all applies even though I know a journal is going to reformat and re-typeset my work anyway.
I fear that, even though I write technical (and not advertising) material, you'd probably not want to receive an email from me, lest I use bold font at some point to highlight a key point or something ;-)