Any supply of money, which is arrived at on the market, is optimal.
You don't need any more money coming in.
So the only thing that increases the money supply does then, the only social effect,
is to dilute purchasing power of each existing, pre-existing dollar or gold ounce or mark or whatever the currency unit is.
So any increase in money supply, increase in goods and services is good, it increases the standard of living.
Increase in capital equipment is good, it increases future standards of living.
An increase in the money supply is pointless, because all it does is dilute the purchasing power of the original and existing unit.
There's no social utility whatsoever.