It's been pointed out in past pages, I believe. Raxxla codex mentions Omphalos RIFT, and I did look through the codex for Universal Cartographics for some sort of rift or split within the company. But they only thing I saw was the name of the CEO, Cynthia whatever, which may be significant but doesn't seem to have any other mentions anywhere else Raxxla-related.
Omphalos Rift is in the same paragraph as Astrophel and Stella, and there was a discussion in the past about Stella's name, which isn't actually spelled out in the sonnets as far as I could see, so maybe we could substitute Cynthia whatever in place of it.
The only other interpretation for Omphalos Rift that I have is, if Omphalos is the company that provided the encryption / data security protocols, the Rift could be a code hack, security breach, or password / cipher decoding mechanism. It's still just vague clues, though, because none of the texts mention ciphers or codes; we're only looking at codes because we know E

is a game.