So, rather than having CR adjustments for each race tier, why not allow different point buy totals for different tiers? (In campaigns that allow point buy, that is.)
e.g.
10 RP - Campaign's standard value
20 RP - Campaign's standard value -5
30 RP - Campaign's standard value -10
40 RP - Campaign's standard value -15
with a minimum of 10 points.
So, a High Fantasy campaign (20 points) would allow Standard (10 RP) races to have 20 points of ability scores, while Advanced (20 RP) races could have 15 points of ability scores, and Monstrous (30 RP) races could have 10 points of ability scores.