To the left of that list I'd put "self-adjusting, without needing a regulator."
Hayek argued that a system of competitive privately-issued currencies would achieve that. I'm not qualified to say whether he was correct, but an economy built on cryptocurrencies would be exactly that.
adjustable, with a benign regulator > fixed > adjustable, with a corrupt regulator
So, the aim shouldn't be a return to the gold standard or a switch to BTC, but to make sure that central banks can do their job without interference from politicians.