He worked for the building of New Starda after the city's destruction, and cooperated with young jihadi engineer Quentin Vigar. He is known to transport war-orphaned children to sanctuary planets, paying the tremendous costs out of his huge inheritance.
After the Great Purge, Bludd asked the League of Nobles to support and receive the human survivors of the former Synchronized Worlds, but his request had not a positive response. With his old friend Quentin, they traveled on his private ship and supplied the re-emerging primitive communities with food, medicine and tools to ease their lives.
On Wallach IX, they observed the devastated planet, although with some recent constructions - build by cymeks. Quentin went to inspect with a scout flyer from Bludd's yacht but was hit by fire. Porce attempted to rescue him but his ship was driven off damaged by fire. He then ran to Salusa Secundus and alarmed Vorian Atreides.
Behind the scenes
Porce is first mentioned in House Harkonnen and implied to be a hero who died during the Butlerian Jihad. His lineage and role is expanded in Battle of Corrin, however it is nowhere stated that he fought in any battle exploits of the Jihad, and he had an activity after the Great Purge which ended the Jihad.
A possible explanation for the House Harkonnen reference would be to suppose that Bludd fought (and was killed) in the Battle of Corrin, but this is not mentioned in the narration.