This is not a new issue, and as far as I can see from a quick search this problem has been there for years but it seems there's still no fix-up?

So I have a desktop (AMD Ryzen 5600X + NVIDIA 3070Ti) and a laptop (Intel i7 8565U + NVIDIA MX250), both with native 4K displays, and both have Linux (Debian/Ubuntu) and Windows installed.
As AMD Ryzen 5600X has no built-in video output/GPU, all display output must be generated by the NVIDIA Card, hence here is the problem:

Although both with native 4K display displayed corrected on GRUB2, the key response (up/down, enter) is super slow (around 1 second delay from pressing the key to the display change) on the desktop.
While on the laptop with Intel CPU, which has built in video output, the key response is just normal (you wouldn't feel lag).

But if I lower the resolution configuration at #GRUB_GFXMODE in /etc/default/grub on the desktop, e.g. to 640x480, the key response would become "normal" without feeling about the lag, but the display quality (font, image, etc) would become "bad"...

This is a general GRUB & HW related issue, as it happens on Ubuntu22.04 / Mint 21 and Debian 11. - Just logging here to see if any workaround? Thanks.