Well, I get it that unusual axial tilt is caused by sth that will be/is explained in some adventures. (BTW, can you tell which adventures?) I don't have a problem with the axis per se, but the combination with other assumptions like one side always facing a sun and difference beetween time of planet rotation and its orbital period, makes it hard to believe or even impossible to exist. AFAIK prerequisites for planet to have one side always facing a sun are the prerequisites that I mentioned in first post. 43 degrees tilt should have impact only on seasons on Lubau (their severity).
I can think about one possibility where planet with such axis would have one side always facing a sun - it's when this planet wouldn't move around the star, what is just illogical and in this situation there wouldn't be such thing as sidereal, so this is not the case.
I was planning to guide my players to visit Lubau, but as GM I just will probably have to improvise and just abandon one or two characteristics of that planet. I just can't explain them something that I think it's impossible (even magical worlds have their own logic). Could you give me any spoiler about the cause of this whole situation, so I won't have to take the whole thing back when I'll eventually buy adventures that you mention?