No RCTs don't take a long time to "read out" especially when they're short in duration like these studies have been.
No, the goal for boosters is to restore waning efficacy which should always have been defined as protection from serious illness, hospitalizations, deaths. The fact they did not conduct rigorous studies looking at these hard clinical outcomes was an egregious misstep from the get-go. The break down of disease severity in young healthy people who catch covid is 20% asymptomatic and 80% mild with virtually zero hospitalizations and no deaths. So, from that standpoint, a vaccine isn't necessary for this demographic. As for unhealthy ppl w comorbidities, sure if you can show prevention of disease and demonstrate blunting of disease severity that's decent justification for vaccinating them. However, we now know the vaccines fail miserably in preventing disease after 4-5 months in these people assuming they harnessed an immune response to begin with which in many cases they don't. So a booster isn't going to help a chunk of these ppl anyway. It's really disappointing to see these points being totally lost on you to date.
Unfortunately, good science and medicine takes time. Heterologous boosters shouldn't be offered if there's no rigorous data backing up the safety and efficacy profile of said regimen. If you're going to make assumptions in place of conducting rigorous studies, then admit that and acknowledge it's not ideal and not appropriate to widely serve as a basis for medical recommendations outside a small population of people who are known to be at very high risk of covid related death/morbidity.
The "numbers" don't say any such thing given that they have not conducted the necessary clinical outcome studies even with the basic 2x shot much less the cumulative risks associated with now a 3x + booster.
you are hopeless. I blame failed education in this country.
Good day