One little detail that I had missed about Moon Boats- they're actively propelled by beams of moonlight deliberately aimed from the Red Moon itself. Thus, the reason why they can't move on Dying and Black Moon days is obvious- there's no light from the Red Moon reaching them. But that got me to thinking about these Moon Boats. When did they come into existence? The secret of them was given to three families (presumably in Darjiin) by the Red Emperor at some point, the Eel-ariash exterminated two of these clans in a Dart Competition at some point after that, and now there's one family in the Lunar Empire that maintains the secret. Some members of these families moved westward to Arrolia during the settlement of those city-states by Lunar refugees, because (and this is another little detail) the Arrolian city-states have their own Moon Boats that they claim were operating in secret before the Ban lifted. So Moon Boats were operating before Yara Aranis and the Reaching Moon existed. So much so good. They probably did not exist for much of the First Wane, since Darjiin only became part of the Lunar Empire in 1/42 (1289 ST).
Moon Boats are, of course, much more reliable within the Glowline, but they are also faster, despite the Reaching Moon thinning and evening out the Red Moon's light. Why is that? Well, here's one theory: the Reaching Moon Temples also act as reflectors, repeaters, and condensers for the Moon Boat propulsion beams. As a result, the light attenuates less and so the "wind"/"current" is stronger.
Is it possible to steal a Moon Boat? MGF says yes, of course. So given that the Moon Boat is actively propelled by the Red Moon... (and possibly by the Reaching Moon Temples) that implies that there are factions on the Red Moon which are actively supportive of any group of PCs that steal a Moon Boat. Moon Boats do supposedly need a crew of a dozen Red Goddess initiates (and thus Illuminates) but there may well be ways around that, particularly if you have an experienced Moon Boat pilot/navigator who can compensate for a poorly-aligned crew.
Presumably, too, it's possible to build Moon Boats that run on light from other Moons, in theory. The Blue Moon, the White Moon... the Black Moon, perhaps, if something like that existed and wasn't an UnLunar fable. In practice, where are you going to get the beams of concentrated Moonlight? Well, the Blue Moon Plateau does have rather a lot of Blue Moonrock, doesn't it? Leaving that possibility aside, perhaps this is why those other two families were assassinated by the Eel-ariash. If you can cut down on the possibility of these blasphemous alternate Moon Boats, you can heighten the cost for supporting the White Moonies, you can nip any thoughts about some kind of Shadow Moon Empire in the bud...
But those are just dreams/nightmares for now. In the here and the now, we have this map:
From the Guide, of course, it shows us... some interesting things. The Reaching Moon Temple in Graclodont is disconnected from the other seven, which may mean something, or it may not. There are no Reaching Moon Temples in Oronin, Doblian, Kostaddi, or Darjiin. There is one in Carmania, one in the Silver Shadow, one in First Blessed, one in Glamour, one in Sylila, and two in the Provinces, at Mirin's Cross and in Tarsh between Furthest and Heruvernalda. Of course, there are also shrines to Yara Aranis and these presumably fill the gaps there. What's that little bump for Tork? I'm sure it's nothing.
There are also Orlanth mountains here, places of power for Storm. The Glowline contends with Orlanth, Moon and Storm tussling with each other, but it's worth noting that there are no Storm mountains north of the Yolp-Imther line. What are those Mostali doing here, for that matter? Is this some kind of map of various mountain-based infrastructural systems? Regardless, we know that Moon Boats outside the Glowline are also very vulnerable to Storm. The Tarsh Reaching Moon Temple, probing into Dragon Pass, almost seems like an incursion, or an invasion, or a gauntlet being thrown down. It's so surrounded by Storm power that it doesn't expand outward from its base border at all, and there's a wedge driven into the distance between it and Mirin's Cross! Wonder what genius cooked that one up?
Now, we know that Orlanthi is worshiped in Carmania (!) and that's north of this line for Storm mountains. So whatever's going on with mountain magic (I suspect that it's a complicated thing indeed) it's not something where the Glowline automatically blocks out Orlanth. But at the same time, if the Sartar Reaching Moon Temple had been brought online... Kero Fin, one of two prime mountains for Storm power (the other, Top of the World, is well out of reach) would have been compressed on two sides. Just when did the Tarsh Reaching Moon Temple come online, for that matter? Is it at all related to the sudden emergence of the Kalikos Icebreaker Expeditions in the middle of the Seventh Wane, almost as if the traditional means of weather moderation, the worship of Dendara and Entekos, had suddenly become a bit... ineffectual? Or, for that matter, to the sudden popularity of Invisible Orlanth in Carmania, that cult which claims Orlanth overcame the Invisible God and thus would, presumably, rule over 
?
A lot of material here to chew over, but here's some more- Yara Aranis doesn't seem to have been all that effectual at directly entrapping Sheng Seleris and the nomads. It came down to Aronius Jaranthir and the Carmanians, in the end. But just possibly, Yara Aranis's web bound together the means by which the Red Emperor returned and the nomads were lured to Kitor.