The total information I find in Verbum Help for Key article is:
This filters which sections are shown and can also adjust which Key Article appears.
Verbum Help (Bellingham, WA: Faithlife, 2024).
All other sections have a sentence or two description in the sections showing under each filter. Key article is shown under no filter. Information I was looking for was whether or not prioritization had an effect on what key article appeared and what happens when the library contains no appropriate article.