For a long time I was dissatisfied with hyphenation for Russian in LibreOffice. All the public extensions didn't help too.
Luckily I found tex hyphenations at http://tug.org/tex-hyphen/ and packed it into LibreOffice extension https://extensions.libreoffice.org/extensions/hyphenations-for-russian
With that extension hyphenations work better. In future I'll try to find some time to make it even better.