XPS 9720 - extremely slow install, then never finishes rebooting

so keep ahci enabled, secure boot disabled, and set fast boot to minimal, since you say you cant disable it…
and try booting into the live usb with this parameter:
ibt=off
here is a link where you add it when booting live usb;
if its again slow, dont bother with install, but download the latest iso from here: 202212061117 - download both zip files, merge them, and use Ventoy to flash the iso and try again - also add the ibt parameter with this iso too …