Thank you for your solution. Super helpful!
I tested it and noticed that if I remove the listing_submit snippet and keep only the listing_update snippet, the fields on the “add listing” form are no longer ordered correctly. They do, however, appear in the correct order on the “edit” form.
Additionally, wrapping the category-specific fields with a condition works only if I apply it to the fields in both the listing_submit and listing_update snippets.
I’d prefer to use a single snippet to simplify maintenance. Please let me know if I’m missing something to have the listing_submit form inherit from listing_update as you mentioned.