HP OMEN 45L summary:
Before Installation
- Disabled Secure Boot.
- Enabled VT-d under BIOS/UEFI.
Installation Process
- No Errors/Warnings.
- Went smoothly.
Stability and Peripherals
- USB Keyboard And USB Mouse Worked perfectly without tweaks.
- System is stable.
- “Qubes Update” Would get stuck at updating dom0 (fixed by
qubes-dom0-updatein a dom0 terminal.), Other Qubes update successfully but they take time to update. - No GPU Artifacts.
- No Application crashes.
- Sound works fine without lag or issues.
Internet and Bluetooth
- Ethernet worked without any errors or hiccups.
- Bluetooth untested.
- Wi-Fi untested.
GPU Pass-through
- Experienced black screen followed by hard reset.
- Reasonable cause: Wouldn’t work due to system having only 1 GPU (no i-GPU).
Browsing - Video Playback
- General Browsing and Chromium applications worked smoothly.
- Video Playback had dropped frames.
- Youtube on firefox had choppy playback, Switching to Waterfox fixed it.
Performance
- Really smooth and fast however Qubes starting takes some time.
- Fans are silent and they are un-tweakable due to lack of drivers for linux. (Decision by HP.)
- OEM GPU fans are tweakable using GWE for nvidia. (Unsafe, GWE has to be installed on dom0! Also GWE Requires NVIDIA proprietary drivers). I personally avoided this step due to safety concerns.
Other
- Grub Installation Works without any issues.
- Motherboard: Stock OEM, (BlizzardOC) HP 8917.
- Specs: i7 12700K (comes with i-gpu but motherboard does not support i-gpus) NVIDIA GPU (RTX 3070 LHR)
Notes for other OMEN 45L users:
- RGB on the desktop can be changed with OpenRGB, However it needs to be installed on dom0 which exposes an security risk! I personally avoided this step.
Conclusion:
- Qubes OS works smoothly out of the box!
- No tweaking needed for basic activities.
I almost forgot 
Here are the documents:
Qubes-HCL-HP-OMEN_by_HP_45L_Gaming_Desktop_GT22_0xxx-20240607-043530.yml (1.1 KB)
Qubes-HCL-HP-OMEN_by_HP_45L_Gaming_Desktop_GT22_0xxx-20240607-051215.cpio.gz (12.8 KB)