Can the Fed raise the M1 money supply permanently w/o helicopter money?
I am going to just discuss the situation for the monetary base, not M1. It is possible that the monetary base and M1 could move in opposite directions.

The following three instruments are the main components of the monetary base.


Currency in circulation: dollar bills, and coins. Currency holdings are the result of voluntary decisions by the private sector, and the Fed has very limited ability to influence those decisions.
Required reserves of banks held at the Fed. In order to increase this, loan amounts outstanding must increase. One can argue that Fed decisions influence borrowing decisions, but it is not something that they can easily directly control. (We would need to go back to the Volcker Fed to see a historical attempt to do this; its effectiveness has been debated. Sorry. no reference handy.)
Bank settlement balances in excess of required reserves (excess reserves). These balances went from near zero to being quite large as a result of “quantitative easing.”


The Fed cannot drive excess balances negative, as that would imply that some banks are short reserves - which is not allowed by regulators. However, it is free to make excess reserves as positive as they wish, as quantitative easing proved.

They do this via:


buying something;
or lending against something (which includes repurchase agreements, or repos).


That “something” is usually Treasury securities, but there are classes of private debt securities is can buy or lend against (as was done in the Financial Crisis). There is no other choice; the Fed does not have a legal mandate to dump money from helicopters (or whatever). So the answer to your question is that they essentially need to buy enough Treasury bills/bonds to increase the monetary base, unless they want to lend against other private debts.

I am not able to give a legal opinion, but it is unclear that the Fed has the ability to not demand payment for matured bonds/bills. Even if they did so, it would just be an irregular loan to the Treasury. (Since Fed profits are returned to te Treasury anyway, there is no point not taking the contractual Treasury payments.)