Yes it is exactly that. The difference being that, unlike originally planned, the Pro1-X does not ship with Lineage preinstalled. It comes with Android and you have to flash Lineage yourself.
While several Pro1-X owners (including myself) have installed the Lineage port and use it successfully (as far as the phones binary blobs allow), note that it is still unofficial and that bugs are to be expected. Sooner or later, it should appear in the list of officially supported ports at lineageos.org -- hopefully then also based on more mature closed-source drivers.
I can only second that