Is Build a Box available on Ongoing?

Yes, Ongoing Subscriptions offers a Build a Box feature (aka: Bundle and Save)

Build a Box allows customers to select a mix of items they will order on a recurring basis.

For example, a customer might want to choose various sock styles or mix and match food products for a monthly subscription.

You can add custom subscription discounts, offer custom frequencies, and choose exactly what products your customer will be able to choose from.

Build a Box can help increase a customer's AOV (average order value).