What motherboard can support dual RTX 4090 GPUs?

Asus has begun offering an RTX 4060 Ti GPU with a built-in slot for an SSD The logic here is the card only uses 8 PCI Express lanes,

I had my finger firmly over buy button for the 4090 ES Reference Design block, until I noticed dreaded is not compatible with FE Two

slot 899 Buy For NVIDIA GeForce RTX4090, RTX4090 FE, RTX4080 FE 3-slot 2-slot Graphic Card IO Shield Back Plate BackPlate Blende Bracket at Aliexpress for

kampung slot If I go for a 4090, 13900K and Z790 board then will I be limiting my SSD? 2 slot, in which case the GPU slot has to drop down to x8 (I don't think x12