Since the currency stock inflation is now under 2%, further adoption will, by definition, see the bitcoin exchange rate volatility continue.

The Bitcoin protocol doesn't get changes to protect "different financial tools". So these tools will need to be designed to be compatible with exchange rate volatility.

Fiat is not compatible with bitcoin adoption. Not just for the reasons you are probably thinking either. How many people who are spending bitcoin are reporting gains when spending? How many people who are earning bitcoin (e.g., freelancers) are reporting that income? Right now that's roughly equivalent to a rounding error of gov't revenues. But what happens when that becomes more common? Bitcoin isn't changing. That means fiat will change.

Eventually, after hyperbitcoinisation has completed, then bitcoin's purchasing power volatility will pretty much track productivity growth in the economy, and thus be much less volatile.