The rare research on how blood doping affects subjects with different baseline Vo2Max tilts more to the direction that the fitter athletes get a lesser boost (in Vo2Max) if same protocol is used.I've read this article. There are some interesting conclusions indeed. TTE increases by half for the same absolute power values (80% of pre-administration VO2 max) and decreases when applying 80% or power relative to the current VO2 max which shows that maintaining bigger power (even if it's still 80% of VO2max) is more difficult and depends on non-VO2 max factors as well. Still, 50% addition of TTE is important - for medium-length climbs a cyclist usually losses 2-3% of average power (i.e. 0.2 w/kg) when increasing duration by half. It would be good to have numbers for 30minute power comparisons. And I also think these numbers could be different for top pros - possibly bigger differences due to their large oxygen demand (effective muscles), which (alongsite lungs) can use EPO even more efficiently.
E.g two reinfused blood bags increased the Vo2Max of 50-70 ml/min/kg guys (on average) by ~ 13-14 %, but Vo2Max of the 85-90 ml/min/kg group only by ~ 3-4 %.
Doesn't give answer to the increases in submaximal power outputs. IMO, even slightly overstated difference, because the Hb in two blood bags likely increased total Hb less in % terms in the superfit group, who had more total Hb to start with.