I think it is unlikely that the 2E/F/G do not have the same skew.BTW Have you checked skew of the LNB?
Though 28.2 has a pre-skew of 7,5 degrees as far as I know; I've read somewhere that 28.5 has no pre-skew? Can someone confirm that?
At your location: -22,7* with pre-skew, -30,2* without preskew.
But in the olden days, Eurobird at 28.5 indeed had no skew, whereas 28.2 did have skew. This may be what you remember.
This difference presented yet another dilemma of what to optimise for.
In my case it was easy, I aimed the dish at and skewed the LNB for 2D, as I seldom watched stuff off 28.5E.