In the .exe bundled installation packages, one could unpack and find inside trans_XX.mst transform files, one for each support language. I used one of them to transform my group policy-based installation, as follows, in order to install Greek:
msiexec /i <libo.msi> TRANSFORMS=trans_el.mst /qn
(The installation was made via a group policy, but in essence that’s what happened).
In LibO 3.5 no such files exist. How should I install a single language in this case?