The point of DSC S1E4 was to show that in order to use the instant travel drive it required the subjection and torture of an alien creature which goes against Federation principles and will probably end disastrously. It wouldn’t be the first time a ship has encountered a new way to travel that they then ignored in the future, or turned out to be evil. There’s a VGR 2-parter that also has a Federation ship using creatures to improve their speed and no one followed up on it either.

Either way, why would Discovery use the drive to explore the galaxy when they’re breaking every law to appease a Captain hell-bent on ending a war using a teleporting ship? Lorca seems upset that he HAS a science vessel, he’s not going to let them actually explore. And I have a feeling Burnham isn’t going to let them use the drive very often as it obviously hurts RIPR.