x8/x4

Hi guys, Asus ProArt Z690-CREATOR WIFI has two PCIe 5.0 x16 slots. Manual says they support either x16/x0 or x8/x8 modes. Does it mean the mobo would not support x8/x4 operation? I plan to run x8 GPU PCIe 4.0 in the first slot and x4 AIC NVMe SSD PCIe 4.0 in the second slot. Now I am aware...