@Liam-Shopify Also encountering this limitation.
Our use case is to conditionally hide local pickup options, because we need custom logic for when inventory transfer can occur (eg. minimum subtotal).
In this case, we also need additional information about the pickup options, such as the address, but this data is not available in the function. Attempting to match IDs with actual locations doesn’t work, because as @Majd_Alsado mentioned, the ID is not available in the function and it’s not clear how the handle is generated. So, we are left with title matching, and adding additional arbitrary data into the titles (such as the location’s state/province) that can be leveraged - not ideal.
Somewhat related to this issue, the selectedDeliveryOption is always null: Delivery Customization Function - selectedDeliveryOption always null. Also, for PICK_UP options, the description field appears to always be an empty string.
And finally, the Local Pickup Delivery Option Generator Function API could be super useful, but has been marked unstable across several API version releases now, with no communication about it on the roadmap.
Some improvements to the delivery customization APIs would be really helpful for more complex scenarios.