It's a shame your memory is so faulty. Have you properly considered any of the studies' limitations, either express or inherent? What were they?
What do the anti-doping experts say? Anti-doping experts of the sort WADA relies on to assess elite performance, like Olaf Schumacher, tell us that the expected blood doping enhancement can be up to 3%, regardless of method. Stray-Gundersen and Levine showed us comparable gains of 3% from hi-lo altitude training with just 4 weeks exposure to high altitude. If we use the same (uncontrolled) measure found in many blood doping time trial studies, e.g. like a recent one conducted by Pitsiladis on Scottish athletes and Kenyan athletes, one hi-lo altitude group of men improved by 6.5% after 4 weeks of altitude, while the Scottish and Kenyan athletes improved 5.4% and 4.7%, respectively, after 4 weeks of EPO. (Note the Kenyan athletes were not really trying, as confirmed by RPE measurements, and were merely tempo-ing the 3K time trials at marathon to half-marathon pace, running about 1 minute slower than their predicted capability, so we must take these EPO results within the context of the limitations of the process used to obtain the data. Note also that the post altitude time trials of the hi-lo and hi-hi groups were confounded by Texas summer heat, potentially making these results potentially slower.)
This recollection is not from studies pinned on my fridge, but just from my memory. It's a shame you cannot remember more about a topic that you seem to care a great deal about and claim to know so much about.
Contrary to "no longer being seriously debated by experts", there were recently two meta-studies reviewing four decades of blood doping studies, finding many lacked controls and were not blinded, and concluded the performance enhancement effect from blood doping studies (i.e. the conclusions reported by "experts" like Olaf Schumacher) was over-estimated. Could that include the studies you have read?
That blood doping effect is insignificant among elite athletes is reinforced by the imperceptibility of any additional significant effect during the EPO-era among the fastest sea-level distance running athletes, who theoretically stand to gain the most from the combined effects of blood doping at altitude. We know non-Africans are doping, and that their doping experience is based on their knowledge and experience that "it works". Russia doped more than the Kenyans are doping now, and there is another current thread about Spain's anti-doping authorities still covering up doping, and you keep insisting that doping prevelance is 1 in 2 athletes, and that experts at the AIU tell us that at least 60% of doped athletes are not Kenyan. And yet, outside of Africa, the blood doping effect that allegedly produce the significant east-African results, is the emporer's clothes among sea-level athletes.
You have failed to follow up on this important question: "What are some of these many ways to reliably estimate the performance enhancing effects of doping?" you suggested I make a point of not seeing. I am insisting on making the point now that I would like to see it -- please draw from your vast well of knowledge and show them to all of us.