Austrians don't advocate for a deflationary currency, they advocate for competing currencies. Rothbard, one of the "pillars" of Austrian Economics, even stated that The Great Depression was due to deflation not inflation.

Lots of people that scratch the surface of Austrian Economics immediately start shouting the ills of inflation and such.

Most "hardcore" Austrians I know would like a currency that's supply grew with economic growth. Economy grows by x measure then so does the currency, to keep it stable.