Mises did not argue that sound money requires an absolutely fixed supply. Gold and silver both increased through mining, and he was not opposed to people choosing between competing monies.
The key point is that new money should come through real work and market competition, not political discretion or debt creation.
That is why I favour a small tail emission. The protocol makes new coins available, but miners still have to compete and expend real resources to earn them. The market decides whether that effort is worthwhile.
Free choice of money matters more than treating absolute scarcity as a virtue.
