I’m using LibreOffice Version: 4.3.7.2 on Lubuntu 14.04.2 LTS.
I looked at ~/.config/libreoffice/4/user/registrymodifications.xcu and noticed that thumbnails are included as part of the file making the file run into a few MB in size.
Is there any way to prevent the inclusion of thumbnail data while retaining the facility to remember “Recent Documents”?
Thanks for reading.
Hi
Since version 4.4 the compression ratio has been improved. See release notes.
Nevertheless there is an option: Tools → Options… → LibreOffice → Advanced → Expert Configuration: Common/Save/Document GenerateThumbnail
Set to false the Thumbnails subfolder will not be created. You still have a preview and recent documents list.
See this answer .
Regards
Thank you 
That works perfectly.
There’s also multiple requests on Bugzilla to have the recent docs, along with the thumbnails separated from registrymodifications.xcu: https://bugs.documentfoundation.org/show_bug.cgi?id=99716