If you want to work from the underlying base of tp, it is probably a good idea to get rid of the myths and go with what is actually there. A scan of the vocabulary shows that it is not more primitive than middle civilizations (‘mani’, esun’, etc.) , that it is not a positive language (one “good”, two “bad”s, death but no life, war but no peace, etc.). It has nothing much to do with Daoism (for whom the idea of yet another language would have been repellent. And so on. It is a (just barely) 21at century conlang constructed by 20th century conlangers, with all their quirks in place. Notice, there is no story to which the language attaches, even. (Several people have tried to write one and always failed.) So most of the talk about what Australian natives, for example, would do is basically irrelevant in a world of GPS and the like. Notice that the language, when used, is not about crops (most of us have never seen one) nor wild beasts (ditto) nor placating the Jubjub (well, more of that, under various names). They are about auto tribes and city streets and the latest tv shows. And, like all the textbooks, they write it in a fragment of the Latin alphabet. (The urge to code conlangs is almost universal among epigones, though creator do it less often: Sonja, Tolkien and whoever inventented Kelen are exceptions.)
From this point of view, i.e., tp as it is, the left to right order and the words deriving from it are pretty automatic (they are almost the only thing that distinguishes left and right, after all ). The ‘lete’// seli’ convention is biased toward the norther hemisphere and not very clear even then, but the two people in the southern hemisphere can lump it (they are used to it by now) and the alternative of map reading, which is up-to-date, suffers from the fact that different countries still use different conventions. And not much else works better. Yes, “east” and “west” should mention the sun and do in full form, but , when the situation is clear, the obvious gets omitted, as always. So, all in all, the system in place works pretty well, as well as most anything else, and so doen’t need more tinkering.