It's always fun to interpret the hints in the codex and other places, but what are we looking for?
I'm not talking about Raxxla being a planet, a ship or a hole in space. I'm talking about what FD are trying to tell us with the hints.
The codex says: "The earliest documented stories tend to agree on several points, however: that Raxxla is a
definite place, and that it holds a mystical secret."
A definite place requires coordinates. Nothing else. Coordinates can be many things though. Regular ED coordinates have a starting point (Sol), a plane (Galactic) and X,Y,Z in ly. That is quite a lot of info to put into mystical hints. It can however be done relatively simple, without using know staring positions, assumed planes and specific units of measurement.
The TDW toast is a possible example:
Starting position: the jewel that burns on the brow of the mother of galaxies
An axis (direction): (from) the whisperer in witch-space, (to) the siren of the deepest void. - Ideally this axis goes through the starting point, but it's not required. Parallel works.
A plane that the axis penetrates: (a triangle formed by)The parent's grief, the lover's woe, and the yearning of our vagabond hearts.
If we could decode all the six bits to systems, we would have an exact point in space.
This is just an example of the amount of information needed and how a hint could be structured. Keep looking.