i end up buying mac mini M2 Pro base model instead LOL.
I connected using HDMI 2.1 port.

But 4K 120hz is just perfect for my Dell G3223Q monitor as per this guy's awesome 4K120Hz macs listing:

Macs 4K120hz monitors compatibility listings

But after much time spent to get that best display settings, i used the resolution of 2304x1296p 120Hz. Because that is the best resolution that I can USE HDR.
by default, if want to get HDR + 120Hz/144Hz, I have to choose either:

1920x1080p (everything is freaking large, no screen real estate) or

3840x2160p (everything is wayyy too small, too much screen real estate)

on other resolutions, HDR option cannot be turned on. 

so the best sweet spot was that 2304x1296p @ max 120Hz. All fonts look pretty damn sharp. Similar smooth scrolling as what i experienced from my iPad Pro M1 12.9 (120Hz ProMotion). Working on Words, Excels, reading PDFs was just a smooth experience! 

I also got the DisplayBuddy app (paid app, about USD22.99 for 2 Macs, got 10% off student discount) to run presets on dimming or brightening the screen during day/night & other settings.

I DEFINITELY cannot go back to 60Hz screen after this. Never ever! 

Just curious, do you connect your LG C1 48" to your Mac Mini M2 via HDMI2.0 port?

If yes, then you might not getting the output (Atmos) you wanted.

but when I read thru few reddits.com, apparently if you connect to a tv/monitor that has a DisplayPort 1.4, you can use the USBC to DP cable (ugreen 8K USBC to DP cable is a good buy) to your Mac Mini M2's USBC4 port and can get the desired output.

But according to rtings.com, this display didn't have DP1.4 port, so I guess either hopefully Apple releases an update to fix this issue in future macOS Sequoia or you gonna have to buy a display that has at least DP1.4.

but on a good note, your LG is an OLED screen, which produces beautiful, crisp, true black display though.