Hello @k_aqua,

Welcome to the Klaviyo Community!

Duplicating and repurposing Klaviyo’s back in stock flow for preorder purposes isn’t possible. This is mainly due to the back in stock’s Back in Stock Delay that is unique to the flow which is closely tied to the back in stock feature.

Though, I wouldn’t see why you wouldn’t be able to either custom code your own pre-order function similar to what’s been discussed in the below Community post:

Similar to the case above, I’ve seen some success in users building a custom pre-order button on their website that triggers an event in Klaviyo. Once the event is triggered, this initiates a flow in Klaviyo which notifies you a via a Notification Action step. This sort of setup is great for an inquiry where it allows your own support teams to reach back out to your customers. 

I hope this helps!

David