you mean like that? View: https://imgur.com/a/pk42sd7the second m.2 slot disables the middle pcie slot.
you can use the third slot but that disables sata ports 3, 4 and 5. but ports 1, 2 and 6 will be usable.
if you can handle losing the 3 sata ports to use the bottom pcie slot, then it'll work.
Can you tell, How bad will this affect performance? using x2 instead of x4 or x16 for sound card?yup that's the idea.
leave middle pcie slot empty (disabled with m.2 drive) and put your sound card into the 3rd bottom slot (disabling sata 3,4,5).
can be tricky reading those charts for sure. they can be so confusing at times it takes more than one of us to read and understand them.