This SPI is obviated by the final iOS 15 Safari design.
Created attachment 437964 [details] For EWS
Comment on attachment 437964 [details] For EWS Thanks for the review!
Committed r282314 (241584@main): <https://commits.webkit.org/241584@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 437964 [details].
<rdar://problem/83017491>