[Quoth]

Smashwords ms doc conversion isn't great, they don't take docx.
SO
Make an epub2 from a docx that uses per paragraph styles and "body text level" for everything except chapters / sections etc, which should be Level1, Level2. Don't go more than 2 levels.

Upload ePub2 direct to Smashwords and Amazon. Smashwords also distributes via epub2 to Kobo, Apple, Barnes & Noble, Tolino etc.
Make a dual mobi (it's old mobi and azw3/KF8 in one file) from the epub2 and direct upload that to Smashwords for Kindles. Don't use that anywhere else.
"Save As" the docx as ms doc and upload that to Smashwords for LRF and PDF, don't use that anywhere else.

So the epub is the master / main ebook format and the source is edited in odt (Writer, with save as Docx and Doc) or docx in Word,

Don't open and save docx or doc files in LO Writer without checking ALL styles & headings and saving in ODT, use "Save As" to export Word Formats.

There is also Google Playstore/Google Books. Only upload epub2 to it, if using it at all and add $1 or $2 to price as Google only takes the Publisher price as a guide. They aid piracy by suggesting PDF by default. Most pirated paperbacks are scanned PDF with an unproofed text layer from OCR.

Proof the ebooks on a real eink based epub reader (not in kepub mode). If you are not 100% sure check the dual Mobi on an ancient Kindle and on a later one that does AZW3, select Publisher mode if any heading styles important.

Check on the eink ereaders that you can change font size, line spacing and margins. Justification isn't so important if it's fully justified, otherwise check they work too especially if it's poetry.

Do not rely on Apps or PC programs or Amazon previewers to see if the ebook formatting is OK.