On the subject of powerful acting bosses:

After Anastasia was killed Carlo Gambino was installed as acting boss for a while (because he was consigliere and could hold the family together) before being confirmed as official.

In the Luchese family in the 1970s, Andimo Pappadio was briefly acting boss while Carmine Tramunti was incarcerated. Pappadio would consult with the captains while making decisions but not with Tramunti. Once a decision was made, Tramunti would be informed of it but he had no say in the matter.

Carmine Galante was an acting boss who tried to appoint himself as the official boss. There were some in the family who regarded him as official (Marangello, Sabella...) but obviously the Rastelli loyalists won out.

Joseph Merlino became acting boss of the Philadelphia family in 1998 when official boss Ralph Natale was arrested, and he was completely running the show (and had been behind-the-scenes throughout Natale's time on the street anyway). Then when Merlino got locked up his acting boss Joseph Ligambi was confused by many to be the official boss and had the ability to turn down guys Merlino proposed to be made, saying that he didn't know them well enough and Merlino could make them himself when he got out.

Vincent Basciano made himself acting boss and was making captains without going to Massino for permission. Then when Basciano was arrested he appointed Michael Mancuso as acting boss and Anthony Rabito as acting consigliere (though part of why he got away with this was due to the fact that Massino was already secretly cooperating and was no longer fully invested in running the family).

In the 2000s, Alphonse Persico retained the title of acting boss despite his incarceration. His father had the official title but it was Alphonse who was in charge of the family and could appoing street bosses like Ralph DeLeo.

Domenico Cefalu was elevated to acting boss of the Gambino family after the January 2011 arrest of consigliere and ruling panel member Bartolomeo Vernace. Though Peter Gotti was (and possibly still is) the official Gambino boss he had no say over how the family was run and final say ended with Cefalu.

Joseph Cammarano Jr was another powerful Bonanno acting boss. Represented a faction rival to the then-incarcerated official boss Michael Mancuso. In 2017 he held a vote of the captains and was elected official boss. Though, obviously now, Cammarano was never recognised elsewhere as the official boss and that title remains with Mancuso. Cammarano, consigliere John Zancocchio and others were shelved when Mancuso was released.