DS9 season 6 and Enterprise season 3 showed that you can do both. Enterprise S3 balanced the episodic and the serialised episodes really well. No reason DISCO S1 couldn't have done the same, for example:
- Discovery receives a distress call from a colony and goes to investigate, believing it to have been attacked by the klingons. When they arrive, the crew discovers no life signs on the planet and a fleet of Klingon warships disabled in orbit. Turns out some weird non-corporeal monstrosities ate the colonists and the klingons and try to eat the crew of discovery as well.
- Whilst trapped in the Mirror Universe, Saru leads the crew on a mission to investigate how the USS Defiant became trapped in the mirror universe leading to an encounter with the tholians.
- Discovery receives a distress call from a colony and goes to investigate, believing it to have been attacked by the klingons. When they arrive, the crew discovers no life signs on the planet and a fleet of Klingon warships disabled in orbit. Turns out some weird non-corporeal monstrosities ate the colonists and the klingons and try to eat the crew of discovery as well.
- Whilst trapped in the Mirror Universe, Saru leads the crew on a mission to investigate how the USS Defiant became trapped in the mirror universe leading to an encounter with the tholians.