Mises and Hayek did, in fact, defend the legitimacy, and even the benefits, of mild deflation resulting from productivity gains.

Mises argued that declining prices driven by expanding wealth and productivity are signals of rising living standards, not economic dysfunction. He explicitly stated, “when prices are declining in response to the expansion of wealth, this means that individuals’ living standards are rising,” and that such deflation is good for the economy. Hayek likewise favored letting prices fall when output expands, criticizing monetary policy aimed at artificially stabilizing prices. Hayek’s “neutral money criterion” held that prices should fall during real growth, and he opposed using monetary expansion to counteract such benign deflation.

The historical record, and their writings, demonstrate that both thinkers supported, not feared, mild deflation booked to real progress, contrary to what you claim.

Below are some links to prove this. Your intellectual dishonesty is obvious, pushing such disinformation to benefit your bias. On top of that, you are a bitter little person that doesn't deserve any further engagement.

Why Deflation Is Good for the Economy | Mises Institute https://mises.org/mises-wire/why-deflation-good-economy

Why Price Deflation Is Always Good News | Mises Institute https://mises.org/mises-wire/why-price-deflation-always-good-news

Declining Prices Do Not Destroy Wealth; They Enable Its Creation https://mises.org/mises-wire/declining-prices-do-not-destroy-wealth-they-enable-its-creation