If that additional layer is indeed for a 2nd M.2, then I would say I like this better than my X570i. Mine has the second slot on the back side of the board like many do, suffocating between the mobo and case wall. This approach would allow for at least some airflow over the 2nd drive, and also wouldn't require removing the motherboard to change ssd's.
Seriously, that is a great idea, Asus already offers the separate Q-Connection plugs, just need two of those and the ability to terminate them cleanly on a group of wires. If your soldering/sleeving game is on point, you need to offer these in custom lengths to the aftermarket
this is similar and I like mine.
AMD Ryzen 3000 series mini-ITX motherboard with Aura Sync, WiFi 6(802.11ax), Intel Gigabit LAN, Dual PCIe 4.0 M.2, SupremeFX and USB 3.2 Gen 2
rog.asus.com