Location of Eliéra

Is Eliéra canonically in the Milky Way Galaxy?

Yes, although it’s far enough from space we have detailed knowledge of today (next galactic arm inwards, essentially) that I have felt free to play fast and loose with local astrography.

The locals call it the Starfall Arc .

Is it known (or defined in 'verse) how the Precursors did long distance FTL? Say, to the next galactic arm?