@progval can you take a look at this, please

Thanks!

Hmm, this syntax is very different from the rest of the crosswalks; but it's also the only one that needs to filter on XML attributes.
How about using XPath instead of the ad-hoc syntax? eg. location/url[@displayName='Download URL'] instead of <location><url displayName=""Download URL"">? This way it uses a more standard syntax and looks as much as possibly like the other crosswalks (which do use / to represent subelements).

Could you link to a reference for the terms you use? In particular, I cannot find anything about the three-letter codes at the end of roleTerm terms.

The codes come from the Library of Congress MARC Relators List, terms/definitions and codes can be found at https://www.loc.gov/marc/relators/