SB - Custom interval and tiered discount support for bundles

A merchant has requested enhanced flexibility for the Bundle feature, specifically the ability to:

1.  Set custom delivery intervals (e.g., every 2 months) rather than being limited to predefined options like monthly or quarterly.2.  Apply tiered discounts within a subscription bundle—such as offering 25% off on the first delivery and 20% off on all subsequent deliveries.

Currently, these options are available for single-product subscriptions but not for bundles. When attempting to create a two-unit bundle, the merchant was unable to:

•   Select a two-month interval, and•   Use the “adjust price after a specific number of payments” functionality.

This limitation significantly reduces the flexibility needed for real-world subscription setups where brands often want to incentivize first-time purchases differently than recurring ones. Enabling these features for bundles would make the tool more robust and applicable for a wider range of DTC businesses.