Zoey doesn't need a backstory, she needs
relevance. She's been out of the MC's life for at least 7 months. More importantly, the MC may just have committed himself to a new relationship. Given that, it doesn't matter how many awesome adventures she's had or how much time we spend watching her in an alien context. What matters is how she fits in with the story we've all been following.
The best way to achieve that is to get her involved in events with the main cast ASAP so she can start forging her own connections. That would let her connections to the MC crop up in a way that advances the overall plot as well. It will still be an uphill climb with such a large cast, but it's the best way to integrate her.
Crashing the story to a halt while DPC plays catchup would be much worse. Sadly, DPC has given every indication the Interlude will be exactly that.