So, I've done some calculations, and with the prices of biomass on the black market, it's not really worth the time to train the samples before reselling. Unless you can get one of the samples with traits that increase the overall cost, at least, like one of the smartasses in the alliance lab.
The best sort of training availlable without cheats seems to be double penetration with L2 optimizer, where you come about 600 credits richer after 20 hours of training. Add 500 more if the sample is naturally sensitive.
Compare that to ~4200 credits per 5 hours of prostituting Head of Research on trash world, or 3000-5000 per slave sold without bothering to train.
It's not so much 'training space station" as "slaving space station" now. Am I missing something? Is the player supposed to choose samples for training carefully? Or is balance just not implemented yet?