How can the Fed enforce exit criteria if they begin yield curve control? Over the past year, the notion yield curve control has resurfaced and appeared on FOMC minutes, decades after its last implementation.
According to the Fed's introduction page:

As the U.S. continued to incur debt, the Fed was obligated to keep
buying securities to maintain the targeted rates—forfeiting some
control of its balance sheet and the money stock. The public generally
preferred to hold higher-yielding, longer-term bonds. Consequently,
the Fed purchased a large amount of short-term bills, which also
increased the money supply, to maintain the low interest rate peg.
After the war ended, FOMC members grew more concerned with addressing
the rapid inflation that materialized. However, President Harry S.
Truman and his treasury secretary still favored a policy that
maintained YCC (which also protected the value of wartime bonds by
implying a price floor). By 1947, inflation was over 17%, as measured
by the year-over-year percent change in the consumer price index
(CPI), so the Fed ended the peg on short-term rates in an attempt to
combat developing inflationary pressures.)

This poses an interesting dilemma in configuring the bounds of the program. WW2 was a one-sided victory with rather clear end date. Yet the fact that YCC continued post-WW2 suggests that terminating the program was difficult. It's conceivable that marshaling the political will to end a program that the treasury likely derives massive utility for operating against a high fiscal-deficit backdrop was a major challenge. This phenomenon is sometimes termed &quot;fiscal dominance.&quot;
A BIS paper goes into great length on the matter. Condensing one of the themes:

For many, a long period of large fiscal deficits and very high public
debt-to-GDP ratios raises the spectre of fiscal dominance. It will in
any case accentuate the links between fiscal policy, monetary policy
and government debt management.

Question
How can the Fed enforce exit criteria without a massive/dramatic macro impairment (such as double-digit inflation)?
History and Theories of Yield Curve Control (20 pages)
https://www.boj.or.jp/en/announcements/press/koen_2017/data/ko170111a1.pdf

Lastly,  as  the  fourth  issue, I  would  like  to  touch  upon  the  relation  between  fiscal  management  and  yield  curve  control.  As  I  noted,  yield  curve  control  by  the  Bank  differs  from  the  government  bond  price-supporting  policies  once  implemented  in  the  United  Kingdom and the United States. While these policies aimed to minimize financial costs of the government, the Bank's current policy aims to overcome deflation and achieve the price stability  target.  Given  that  the  policy  directly  sets  the  long-term  interest  rates  as  its  operational   target,   however,   it   is   undeniable   that   the   area   deeply   related   to   fiscal   management expands. Not surprisingly, therefore, there are voices of concern and criticism that  the  current  policy  coincides  with  money  finance  or  monetization,  or  that  the  exit strategy of  the  policy  will  be  constrained  by  consideration  for  fiscal  management.  It  is  therefore   important   that   the   Bank,   bearing   in   mind   those   voices   as   well,   gain   the   understanding  of  the  markets  and  the  public  by  releasing  more  carefully  than  ever  the  information on the purpose and ways of thinking about monetary policy implementation.

Quantitative Easing: Entrance and Exit Strategies (16 pages)
https://files.stlouisfed.org/files/htdocs/publications/review/10/11/Blinder.pdf

Because many of the Fed’s unorthodox quantitative easing policies put taxpayer money at risk, these policies constituted quasi-fiscal operations — equivalent to investing government funds in risky assets.

I would argue that there was less spare capacity in the economies after World War 2 due to destruction of assets in many countries and due to wartime restrictions of consumption and investment. Also the household sector in the United States emerged with a relatively clean balance sheet where collateral assets were not saturated with private debt. By contrast the economies with QE today have spare production capacity and assets saturated with greater burden of private debt. I am not aware of any econometric series that compares the private debt to government debt. Rebel economist Steve Keen publishes some charts making these comparisons of private to public debt but I have not drilled down into his sources of data.