A jury at Leeds Crown Court convicted the three men of killing the 33-year-old in his cell in November last year. The judge told them none will ever leave prison.
A follow-up inspection found the high-security prison now holds men convicted of sexual offences in separate units, but progress on most earlier concerns has been limited.
Tom Wheatley of the Prison Governors Association says some long-term prisoners in high-security jails see attacking infamous offenders as a way to gain status.
Inspectors found the West Yorkshire high-security prison under strain, with failing infrastructure, rising violence and poor access to activity, although health care had improved significantly.
The inspectorate's report on HMP Wakefield, published in February 2023, found a settled high-security prison with good key work, but half the men locked up during the working day and serious health care shortfalls.
