The 12th Arifureta novel is unexpectedly not the last in the series (if the afterword is to believed, the 13th will be)… that said, it does wrap several things up and expand upon a few things mentioned in passing earlier with all that’s left being the Hajime/Ehit confrontation. While better than the previous novel it ultimately feels like a stalling action however, and I would suggest holding off on reading it until the conclusion is available.
Kumodesuga‘s 14th entry is also a bit unexpected in that it spends something like half its page count on detailing the world’s pre-system history and Ariel’s past in particular rather than advancing the timeline much. It does advance a bit though, enough to provide a conclusion to the Potimas conflict at least. The actual conclusion of the series will apparently be spread out over two more novels which were originally released within a month of one another. So here’s hoping that stays true for the translations as well (although ideally I’d prefer they be released as a single novel).