> nd what - if any - role their openness to a certain anti-parasitic, protease inhibiting drug has played in their success.

There's a trial study currently in progress in Japan to investigate this, but all the evidence we have points to ivermectin being of no benefit to Covid patients unless they have parasitic worms. See, for example: https://astralcodexten.substack.com/p/ivermectin-much-more-t...

It's not an unanswered question, in other words. Ivermectin doesn't help against Covid.