Acorn I understand that xara upon publish presents both webp and jpg images.
I’m thinking of hero images only. On this page only. https://melfortmuseum.org/index.html The fire engine picture is webp only. The page after menu corrections from yourself and egg is greatly improved.
If larger image elements are not used for transitions, or pop ups, simply as hero webp, the page tests well. Cascading certainly would be an answer.