Running an Asus z370-a with 4 vegas inside of it. No problem with the mobo (although these Frontier Edition Vegas are a nightmare to work with)
I do all of this in bios on start
1. update bios
2. enable 4g
3. turn everything to gen1
4. disable unused usb
5. kill onboard audio
6. turn on igpu
thats just me, i know others have variations but thats allowed me to run the z370-a fine
does the 1 x PCIe 3.0/2.0 x16 (max at x4 mode) slot support a gpu?