I'm aware of Far Trek. Are there any other unofficial Star Trek RPGs that should be on my radar? (I know I missed an excellent opportunity for a pun there.)
SOmeone's done a 3rd edition of FASA Trek -- sufficiently updated. Essentially a derivative work. Lots of changes, still recognizably F-Trek. https://www.jackphoton.space/Far Trek and Where No Man Has Gone Before are the two unofficial ones I know about that are complete standalone games. There's heaps of homebrew and house rules turning other systems to the task. Tons of tips and pointers for using generic systems for Trek as well. Popular choices are Savage Worlds, Fate (especially with the Brainstorming mechanics from Atomic Robo), and Cortex Prime.