The 3080ti comes with 4 ports - 3xDP and 1xHDMI and all are active by default. The mobo ones are dependant on the mobo and the CPU - some do not have built-in graphics ability, the 12900K does, the 12900F does not.
I did use a dual port USB-C to HDMI adaptor (pluggable) at first but Windows 11 sometimes dropped it on boot and it took a bit of fiddling to get going again. The performance hit with the CPU graphics and the USB graphics is identical so I’m unsure if the USB device uses the CPU graphics or not.
It really works the system when you load so many screens but it all plays well together and makes a very nice setup I think.