Lots of languages have more than one transliteration scheme. Is it Mao Tse-tung or Mao Zedong? Is it Tchaikovskii or Chaykovsky? Is it Genghis Khan or Chinggis Khan or Jenghiz Khan? Is it Qaddafi or Gaddafi or Gadhafi or Kadhafy or Kathafi or...? Foreign sounds don't map exactly onto English sounds, so there's often more than one way of approximating them. And of course one language can have different regional dialects that the various different transliteration schemes are based on.
To be honest, I don't see why Nasat names would be based on English letters at all. But given how alien they are, I'd expect their language to be at least as difficult to transliterate into the Roman alphabet as Mongolian or Arabic is. There could easily be a variety of schemes favored by different scholars or different style guides. Perhaps Pattie prefers to transliterate her name as P8 Blue rather than Pee/8/Blue in order to avoid childish jokes, or perhaps transliteration conventions changed between 2270 and 2376 (much as the Pinyin transliteration of Chinese has now come to be favored over the old Wade-Giles system, which is why we now speak of Beijing instead of Peking).
But I just went with the spelling (or rather, the punctuation) from the Foster Logs
because I'd read them recently and I'd forgotten that the spellings he used were often nonstandard (though I think the reprint editions fixed some of them, and I read his adaptation of "The Jihad" in a reprint edition). It was a passing reference so I didn't research the issue in depth.