Apologies for cross-posting:
Because we will shortly be implementing Primo, the Ex Libris library discovery layer, I contacted archivists via A&A and Twitter for examples and experiences with indexing and displaying archival descriptive metadata in Primo.
While only a minority of the installations are indexing EAD in Primo, I think it is worthwhile looking at the variety of approaches they have taken. Most institutions are indexing MARC data.
This is a summary of responses:
I'd like to thank everyone who responded to my call. You were all so very generous with your information!