Wow, that was a long time ago now. Still holds true for Gtl, PnG & GTR2, though a 2cm ride height difference is more normal for me (than the 3cm I suggested back then).
As good as (I think
) that guide is, I've never gotten my head around how best to setup for bumpy tracks (which is more to do with "fast bump/rebound" I believe.
I guess when I'm setting cars up, I'm looking to make car safer anywhere I'm struggling & enable me to attack better & grow confidence at key places. Not forgetting I try to even out front vs rear tyre wear so I don't get surprises late in a race.
Hope it helps even a little maybe