This is a comment for anyone else looking to replicate the “Featured item” checkbox from Omeka Classic in Omeka S. Adding the Featured property from the Curation vocabulary (this can be made private if needed) will allow a certain item to be featured. In a Browse Preview block, change the Search query to:
sort_by=curation:featured&sort_order=desc
I entered “y” into the Featured property field for my featured item, but this will sort items with any text in that property, then sort the rest of the items based on the default, date created. Any other property should work as long as the search query grabs the vocabulary and property. This took me a bit of trial and error because I couldn’t find a resource that lays out the syntax of the search query. Hopefully it helps someone else.