Zbook Power G10 HDMI 2.1 output spec for 4K @ 120Hz

[Deeko76]

I have the HP ZBook Power 15.6 inch G10 Mobile Workstation PC IDS Base Model , product number 7C3M3AV: https://support.hp.com/au-en/product/product-specs/hp-zbook-power-15.6-inch-g10-mobile-workstation-p...

It has an i7-13700H, 32GB Ram and an A2000 ada GPU. I was given it through work and would prefer to use it on my external 4K @ 120hz monitor. I have found the USB-C 40GB/Thunderbolt 4 port will output to my monitor at 4K @ 120hz but the laptop's HDMI 2.1 port will only go to 4K@60Hz. I have all the proper cables etc. and tried it on two separate monitors and different cables but it will not go above 4K 60Hz using the HDMI 2.1 port. Is the HDMI 2.1 port full spec or is it some kind of cut down version? I also cannot set the dGPU (A2000) to be the primary GPU for setting the desktop settings and sich and for outputing to the external monitor (I much prefer to use Nvidias control panel for desktop settings, not Intel's), it always defaults to the Intel Iris integrated graphcis which is frankly rubbish compared to the A2000 ada GPU. 

My three questions:

1. What is the actual spec of the HDMI 2.1 port on this laptop and can it officially meet the HDMI 2.1 spec with 4K @ 120hz
2. How can I disable the integrated Intel graphics and solely use the A2000 ada GPU so I can use it directly for outputing to external monitors and such, and use the Nvidia control panel for colour settings, resolution etc.?
3. When playing games to the external montor (resolution set at 1920x1080 @ 120hz) through the HDMI port, it always runs at 60hz on the display (tried multiple displays. Again, the monitors and cables are all full spec for HDMI 2.1. Is the HDMI 2.1 port limited to 60hz?

I am starting to think the A2000 ada GPU is not directly connected to either the Thunderbolt 4 or HDMI 2.1 port and instead  it does its high performance rendering for professional work or gaming with the video ouput directed back through the Intel Iris integrated GPU to the externally connected monitor? 

Thanks!