(This was a late-night thought, the basic premise of which is that Wadi el-Hol might more squarely fit the after-Sinaitic and before-Arabian writing period - placing it anywhere from possibly around 1400 to 1200 BC).
I think I can now show, just as I will no longer foreseeably have time to do so, that the idiosyncrasies in connections between the Wadi el-Hol Inscription and Ancient Arabian are not so idiosyncratic. In short, one core assumption regarding Wadi el-Hol may not best fit the reconstituted facts given this outlook. Namely, Wadi el-Hol may not be particularly ancient.
In fact, the presence of a distinct ḥ nowhere present in Sinai - which can be more reliably placed within a range of 1700-1550 BC, squarely within the Hyksos and Intermediate periods. Conversely, the earliest evidence of Ancient Arabian writing - in this regard - comes perhaps just ahead of the cusp of the first millennium BC and is in a number of ways dissimilar to these earlier trends. Before that, several anomalous but linear alphabetic (i.e. not the workers' graffiti) were purchased in South Egypt by Petrie. These reveal no obvious h connection to Arabian or Wadi el-Hol, but rather seem more Canaanite or perhaps late-Sinaitic. Conversely, in other ways their paleography is undeniably Arabian (particularly S1 and Z).
But the Wadi el-Hol h was not a suggestion in a total vacuum. The anthropomorphization juxtaposes it with the 'worshiping-man' ḥ, and its grammatical context seems strong. So that Jamme 863 is apparently archaic and squarely in Yemen is pretty odd - particularly if the h present at Wadi el-Hol is also present there. But moreover, that same h may have been used as the Ugaritic alphabet's ḥ, and vice versa, sometime (realistically) between 1200 and 1150 BC in Coastal Syria.
So what we actually have here is a reasonable geo-temporal range: Sinai Peninsula - 1700-1550 BC, South Egypt - (perhaps) 1400 BC, Yemen (perhaps) 1300 BC, Coastal Syria 1200 BC. The core question is whether the evidence for the dating of Wadi el-Hol to 1800 (or 1800-1700 or whatever) BC is strong - particularly given it is based on an unknown language and no agreed-upon translation, nor any physical evidence. It might make more sense to interpret the other South Egyptian texts as indicative of the spread, within Egypt, of this primarily Semitic fad of writing in alphabets particularly after the collapse of the Hyksos.
That these don't exhibit the later connections leading to Arabian in some regards, but rather a closer connection to Sinaitic and even Proto-Canaanite is interesting. It suggests the possible cross-pollination of perhaps individually-spread alphabetic traditions within Egypt after the collapse of the Hyksos. The contexts tend to be religious, although nothing can be said for certain. However, Egypt had large communities not just of expatriate workers but also educated entourages from Northern principalities. This could, for instance, account for possible evidence of Mesopotamian (writing) influence on Wadi el-Hol and later inscriptions.
Hiring Canaanite shamans was not unknown, so some scribes from the Sinaitic period might have found purpose there. However, the Wadi el-Hol Inscription is also definitive evidence for nomadic use of the alphabet (probably the earliest definitive use) in that it occurs at or near a shrine to Hathor on a desert road used in a pilgrimage between Hu and Thebes. Whether the author (probably Syrian or Syro-Arabian) was a 'permanent resident' of Egypt is immaterial. The inscription itself was carved in transit, almost certainly for religious ritual.
This rethinking came as I was working again with Jamme 863 - trying to firmly translate it to South Arabian. "With the people of (maybe) Fatihan, Yahmad respects that this is a protected BRN." This may have been on or near a building called BRN, or this place or region might have at some point been called BRN. Fthn is listed as the name of a valley of unknown location in a text from roughly 280 km southwest of Jamme 863 and BRN is used as a name for both a place and building within a similar radius. So it may simply be the case that this inscription is early and anomalous.
But it still doesn't refer to my opinions of the Wadi el-Hol Inscriptions - or it being a hoax. So it was kind a scam-title. The hoax aspect is that the inscriptions may simply be from the early New Kingdom or very late Second Intermediate Period, when relations between Syria-Palestine and South Egypt would have increased, realigned, and renormalized. Similarly, it is during this period that the myth of this wandering goddess is better known, thereby negating the possibility that Egypt may have in fact borrowed the myth from this Wadi el-Hol author. The more logical explanation is not (per se) that the strong evidence I've gathered for the character-identifications is wrong but rather that their relationship in the broader scheme was.