I think can fit right under vid card in PCIx (small) slot. The usb cards are very small and parts all project below the board and slot, so should fit. If you had to, looks like you could even put the wifi card under the vid, I cant be sure.
Again short advice first. If this works I would try using the card ports only. Forget the mobo ports that W10 can mess with. Most cards have 4 ports.
I'm no expert how to fix W10 permanently, likely no one is. See all the issues in my link above, failed fixes, or where problem returns. That thread is older, but now google "windows 10 turns off usb ports" & use tools for past year time frame. 2 fixes on top. In Dev Mgr expand USB Controller, right-click and "Update". Restart. & Good luck to you. Also go to Advanced Power Management, find "USB selective suspend setting", choose Disabled, OK, and save settings. There may be more.
How good are these fixes & what about shut-down, change devices etc. Why should a user have this nightmare as only MS can create? I have one W10 system I was forced into & have not had usb problems but I am using simplest mouse & kb only. I think a lot of this is about the devices, maybe or especially rgb.
btw I'm only into this bc I want to put a newer gen mobo in a W7 system. If you try a pci card pls share your results.