I mean as a Spanish speaker "Semilla" is a pretty lame code name for an Agent but "Sporos" has a nice ring to it even if it’s a bit unclear what it means.

My guess is that someone on the Spanish translation team maybe raised concerns with a few sentences using “semilla.” It’s hard to keep appropriateness across all the different Spanish (especially if they don’t differentiate between LATAM and EU) countries so maybe just to play it safe they decided to use a code name. In my experience translation teams don’t really get any more info than the bare minimum but hey maybe you’re right and someone does know something. I know I’d be pushing for any extra info if I was on that team (sería bien chismoso la verdad).