Look closer at the history of colonial fiat and inflation - it worked well in general - but certainly suffered with wars.
Strict controls in place were the key. Those controls kept the inflation in check as script had a set value in goods - as people lost faith in the issuer ability to pay though inflation factored in heavily .
What? No one lost faith in Colonial Script. It was done away with when Ben Franklin became ambassador to England and upon his arrival there asked how could there be so many homeless and such poverty in the richest country in the world?
To which his question was met with a don't you have poverty and homeless in America? When he replied in the negative, they asked how is this possible and he told them Colonial Script is printed only as needed, there is no one homeless nor is there any poverty.
When they heard this, they went to their king and told him they must get America on their financial system in order to control them. Thus, was Colonial Script done with and we got the English debt system and instantly we had poverty and homeless just like they did.