Mm good points. If I were dictator, I would still have a variolation process at least tested and developed for each new pathogen, which could be deployed as an emergency backup.
If by threshold you mean the percentage thing, I would say that at 25% conterfactual harm, variolation is a reasonable option for countries that couldn't manage vaccines, if nobody else was going to give it to them.
Re 1: could it work as opt in? The brave go first?
Re 2: Wait why do you need to do that? Maybe you can have a sick person sneeze into a napkin and immediately rub it on the next person or whatever, so there is no intermediate storage step? Wrt biosecurity, a high percentage of the population was going to get covid / it's an available everywhere already anyway ?
Re 3: Have a private actor do it on govt contract? Competing firms ranked by effectiveness and safety etc
Re goalposts: What are you viewing as the goal post? I think I misunderstood you somewhere. What things are you viewing differently?
Yeah this might be getting out of scope for the discussion but a good variolation technique have no manufacturing, no patents, no buying / selling negotiation. Random people in poor countries with almost no govt could variolate each other. If world order or the science machine breaks down (new pandemic kills all the world leaders or something) then the technique can still be used.
And to get more out of scope, what's the harm reduction of a vaccine? Let's generously say the cost and side effects of getting vaccinated are 1% that of getting the disease itself. (Ignore spread reduction benefits for now.) At what percent would you consider variolation worthwhile as an option: 30%, 10%, 5%, 1%?
Couldn't eg India have variolated their entire population and developed a robust process for it within a month in March 2020?