A convicted terrorist was seen as a "success story" for an educational project prior to killing two of its members at London's Fishmongers' Hall.
Usman Khan stabbed Jack Merritt and Saskia Jones to death at a Learning Together event in November 2019.
The inquests into their deaths were told Khan was allowed to join the programme despite "concern was he was a (terror) offender".
It was thought the risks he presented were "controllable", the jury heard.
Khan, from Stafford, became involved in Learning Together while serving an eight-year prison sentence for plotting a jihadi training camp in his parents' homeland of Pakistan.
The scheme brings together offenders and people from higher education to study alongside each other.
Jurors at the inquests at London's Guildhall heard evidence from Will Styles, who was governor of HMP Whitemoor in Cambridgeshire before Khan's release in December 2018.
Mr Styles said: "Learning Together had been a hugely positive experience, and it is fair to say Usman Khan had been seen as a success story at that point in time.
"I was enthusiastic about Learning Together, I am enthusiastic about anything we can bring into a prison which helps rehabilitate men because most of those men will be, at some point, living in your town, in your city, in your street."
He continued: "The concern was he was a (terror) offender. Consideration was given to risk, opportunity, benefit."
Mr Styles told the inquests it was concluded that Khan should be able to join Learning Together, despite intelligence that he had been involved in radicalisation inside prison.
He said: "I thought the risks presented were controllable and the potential benefits for Usman given his fairly imminent release - I thought it was a positive opportunity for Usman and for us."
The jury were shown a draft of a letter seeking an award for Learning Together's work at the prison, and Mr Styles said that although the project was no longer running at Whitemoor, its impact had been "amazing".
"It's very difficult to set aside the impact of the Fishmongers' Hall attack, but if I was able to do that I would say the feedback of everybody involved - staff, Learning Together attendees, prisoners - was absolutely outstandingly positive."
Khan was considered such a success for Learning Together that he was invited to the event at Fishmongers' Hall to mark the programme's fifth anniversary.
Nick Armstrong, representing the family of Mr Merritt, 25, suggested that Learning Together had sought to use Khan as a "poster boy" for the programme.
"Learning Together had been a hugely positive experience, and it is fair to say Usman Khan had been seen as a success story - I wouldn't say a poster boy - at that point in time," Mr Styles replied.
Khan armed himself with kitchen knives and killed Mr Merritt and Ms Jones, 23, and injured three others, before being chased and disarmed on nearby London Bridge by three men armed with a fire extinguisher and a narwhal tusk.
He was then shot dead by police.
The inquests continue.