Ashly Burch originally reprised the role of Mayuri in the English Dub, but had to drop out halfway through due to Scheduling Conflicts. She was replaced by Meagan Shipman, who according to her Twitter, watched every episode of the Original Series & what was aired of 0 at the time in under 2 days to prepare for the role.
DURPA (Defense Ultimate Research Projects Agency), mentioned in the anime is a reference to DARPA (Defense Advanced Research Projects Agency).