Hey, @Sharon15 .
Thanks for joining the thread, and I’d be happy to add you to the feature request.
The ability to edit orders was released well before the local delivery and pickup features, so it’s likely that the latter still needs to be developed further. While I’m not able to say why it’s harder to implement nor am I able to provide an ETA for this feature request, we’ll be sure to announce on our changelog or updates page if Shopify moves forward with any changes to the platform.
If you’ve any other questions, don’t hesitate to let me know.