Currently the only method that allows an iframe to render in Xerte, and zoom to persist in GitHub Pages:

https://universalviewer.io/uv.html?manifest=https://librarysearch.cardiff.ac.uk/view/iiif/presentation/44WHELF_CAR/[paste mms]/manifest?iiifVersion=2

Load object, zoom, copy url - (in Xerte, coordinates don't persist, skip this step)

Xerte code (add end brackets): iframe src="[paste url]" width="100%" height="600" allowfullscreen frameborder="0">

GitHub pages code (add end brackets): iframe src="[paste url]" width="800" height="600" allowfullscreen frameborder="0">

Xerte removed link code (from title entry, add brackets): a href="https://librarysearch.cardiff.ac.uk/view/UniversalViewer/44WHELF_CAR/12213065390002420" onclick="window.open(this.href, '', 'resizable=yes,status=no,location=no,toolbar=no,menubar=no,fullscreen=no,scrollbars=no,dependent=no,width=800,height=600'); return false;"

embed 800, one image

UV test

embed 800, one image, zoomed

embed 800, two images

embed 800, two images, zoomed

embed 800, two images, preserve zoom, zoomed

embed 560, two images, preserve zoom, zoomed

embed 560, two images, preserve zoom, zoomed

embed test, zoomed, two images>