Hello everyone!
Big thanks each of you for this unique experience and information!
And here is mine piece of exp 
My spec:
- CPU Intel i9-10940X
- M\B WS X299 SAGE/10G (No internal video)
- VGA 2x Nvidia 3090 (Gigabyte, Turbo edition)
The Problem:
There is no video signal in KVM while booting, signal comes only after loading a system (Ubuntu 22.04 in my case).
Can’t see ASUS logo, where i need to press DEL button to go into the BIOS settings (technically i can, keyboard and mouse are functioning, but i can’t see anything, even the moment i should press the DEL button).
The Cause:
When there is external or internal video adapter, usually (in BIOS) you can pick which video input i’ll use - exeternal or internal. If PAUL is not the main video input, you wouldn’t see anything while boot process, nither in KVM nor in VGA output of PAUL, only after system boots video driver will start and you will be able to see a system screen.
The Solution:
- In BIOS switch video input to PCI slot, where PAUL is inserted
-
VERY IMPORTANT THING!!!
You should switch VBIOS Jumper to dedicated VGA BISO ROM (he-he, official documentation typo)
Hope it will help someone!
P.S.
Also i upgraded FW to L1.10.00 from post earlier in this thread and it seems to work great.
Any questions are appreciated!