If I do a “minimal install” of 18.04b1 then use the Software Boutique (17.10.16) to install individual omitted packages, LibreOffice cannot be installed from it because there is no button to do so - only a Details button. For some reason, LibreOffice Base has both buttons.
Every other initially omitted package (vlc, Redshift, Thunderbird etc.) offers both buttons.
This behaviour persists after doing a software update (as of last night).
(This is probably a big use case - doing a minimal install then installing a subset of the packages that would have been installed by a full install is likely to be a thing).