Crucial is it? I see it as a tangent; an unnecessary one. Digitals? c0da? What am I supposed to do with this? anolyze it? The only concepts in the Love letter are just rewordings of past topics. Put 5E on it and suddenly it's noteworthy. Slap in some completely alien terms and suddenly it's profound! I don't buy into this hype, nor will I ever join the throngs of Love letter forum philosophers.
Who says we want you? I'm not even sure we're big enough to be called a "throng".
As for whether it's profound or not, that's a statement people might make about it, not something that it itself makes.
Forget about the funny terms. That's for local colour. It's unnecessary as all ornamentation, which is to say it's not, and they're likely to be elaborated upon in future texts anyway. Most of the loveletter is interpretation of certain passages in the Sermons. What's crucial is that it tells us more about the cosmology than we knew before. That people go to Oblivion or Aetherius when they die and then get recycled. That this eternal return is something from which we need escape. That the Numidium, the Tower, the Enantiomorph, CHIM, etc, are all attempts at this escape, information that when combined with other texts, show that the means of escape can be seen as a struggle for identity amongst many (two headed gods, many-souled face of walkbrass, the many souls of the amulet of kings, the towers as symbols of cultural variance, etc) . The last step is to become the world that you are in a state of hallucinatory onanism. What's more, it also tells us what the future is going to be like, and it sounds kind of bleak.
Some of this was explored later (I think? I've never been sure which came first, the Loveletter or the Teachings) and more transparently in Vehk's Teachings. Still, I wouldn't call the loveletter pointless. If Vehk's Teachings are an explanation of the themes in TES lore, then the Loveletter is a personal exploration of them. I find the stream of consciousness bit at the end rather emotional and stirring. The writer gets caught up in his vision and begins to describe a thing only possible in languige liquid, plastic and dreamlike until finally any attempt at language fails, breaks down, and ends with a beatific summation; "GOD IS LOVE".
And it's also a birthday gift to Kurt, which is kinda nifty. And yeah, I like it.