I have been searching for a full soundtrack somewhere to at least purchase but I'm getting no results. Maybe that speaks for itself and tells me that it was not released, but I figured I should ask here before giving up. Anyone know something about it? Or should I give up?
As of current writing (June 2019), no, Kino no Tabi (2017) hasn't released its OST yet.
From the anime's official site (Japanese), the only product listed in the Music category is the OP&ED CD and the limited-edition DVD (which contains the MV for here and there).