I don't think it matters whether Galileo or Sabre is the source. What matters is ability to request specific fare classes... in particular those used for award classes (which may require "direct connect" feature).

On AA we want to see A, C, T, U, X, Z
On UA we want to see R, X, O, I, N, E
Don't know about DL, CO, NW or others.

UA never worked on aeroplan's Galileo tool, but is visible through UA web site if you try and book an award ticket in expert mode (only if availability for the award you want is not zero)

Thanks, DAK