Your question is a fair one. It is the wrong one, but I understand where it comes from This is a bit of a sidetrack, but the only way to answer the question is to look at the history of the term “inflation”.
Originally, “inflation” was a term to represent the introduction of money into the money supply. Over time, it came to mean one of the potential consequences of that introduction.
Modern Austrians draw a distinction by referring to the latter as “price inflation”. They view this as a consequence of policy. You, and mainstream economists, don’t even have a word for the former “inflation” as far as I know. In any case you view the latter “price inflation” as a variable to be manipulated rather than as a mere consequence or symptom (to a certain degree, you know how to manipulate it using policy so to that degree you understand it as a consequence)
A lot of people think that Austrians are so concerned with price inflation. They are concerned, but to them the enemy is the old-style inflation.
This inflation can occur in a free market money regime when gold is mined. This is not a concern as the production of money occurs on a profit/loss basis.
When caused by artificial credit expansion, old style inflation results in malinvestment because there is a discoordination between what the market signals are saying about savings and the realities of what has been saved. Specifically, artificially low interest rates tell the market that there are more savings than there actually are.
The old style inflation can result in price inflation as measured by CPI. It can not result in that. Austrians will not come out and say it certainly does. They will state it as a counter factual. They will say price inflation as measured by CPI will be greater than it would have been in the absence of credit expansion.
This is important because there are so many moving parts in an economy. Chief among these for this discussion is productivity. In the absence of old style inflation, prices go down in a healthy economy because of gains in productivity. Think late 1800s when even Friedman admits it was a great time of growth even though there was no price inflation and sometimes price deflation.
The Fed has expanded and enables the expansion of the money supply greatly. From that standpoint it is definitely inflationist in the old sense. It is also inflationist in that it has created price inflation that is higher than it would have been absent its policy.
Think about the 80s, 90s, 00s, and 10s. I mean really think about the leaps in productivity that have occurred. There are tech people that could better explain how computing and the internet have so increased productivity as to boggle the mind! Japan and the growth of the Toyota production system. Billions of Chinese deployed in ever more efficient occupations. Krugman could tell you about how great the fax machine was.
The point is we should have had the most glorious deflation in world history. We didn’t because the Fed has been busy pumping dollars out like crazy.
So back to your question. There is no preferable rate of price inflation to be manipulated. Allow inflation to occur with the production of money on the market. What comes will come. The benefits would be avoiding rampant malinvestment and glorious deflation.