After almost giving up on the KPs and reboots (after using the latest Skylake+ premade and sanity-checked) on my Kabylake / 100 series motherboard, I'd managed to get this public beta installed (from Apple servers) by using the Haswell package - after a last attempt. Added in the Realtek RTL8111 LAN driver for networking, however USB WiFi driver installation still causes KPs on boot. Might be a booter quirk configuration or something. Will revisit on a later date