Dual Monitor 3440x1440 support for M1 Mac mini

Check the M1 Mac Mini Video Support at > https://www.apple.com/mac-mini/specs/

Be aware that one Display must be connected to a USB-C port and the other to the HDMI port.

see > https://support.apple.com/guide/mac-mini/connect-a-display-apd8e4fbbb97/mac

Click on this link to read how to 'Use external monitors with your Mac' --> https://support.apple.com/HT202351

Check video support under technical specifications on the product-ID page

Identify your Mac mini model - Apple Support

What model are the LG's that you are looking at?

Knowing the input connections of the LG displays is important, because the M1 Mac Mini only supports one display on the USB-C./Thunderbolt port and one display on the HDMI port.

You're welcome.

You can put one of those LG displays on the Mac Mini's HDMI port using a Premium Certified HDMI cable.

Then you can put the other LG display on one of the Mac Mini's Thunderbolt/USB-C ports using a USB-C to HDMI adapter or a USB-C to DisplayPort cable.

It is possible to run three monitors with an M1 Mac mini.  Here is my set up in a flight simulator. My 16 GB M1 Mac Mini with OS Monterey is connected to three monitors, all of which work, as follows: 

(1) To a Dell model 2007 FPS monitor (1600 x 1200 @ 60 Hz via VGA on monitor to VGA/DVI-I adapter to Startech.com USB 3.0 Dual Head Graphics Adapter to USB-C on Mac Mini).  DisplayLink driver from startech.com was loaded and activated.

(2) to a Westinghouse TV model LDD2240 (1920 x 1080 @ 60 Hz via HDMI to HDMI).

(3) to a Flatron W2252TQ (VGA ơn monitor to Belkin VGA/Thunderbolt adapter to Thunderbolt on Mac Mini). 

The three monitors do not all start up simultaneously, but all three come on in about a minute, with no further action on my part.  It is as though they need to figure who is the boss.

Is there any benefit to connecting my Dell S2721QS 4K/ 60Hz monitor to DP from the USB-C port on my new M1 Mac mini Vs the HDMI connection?

USB-C to DisplayPort offers more resolution options and higher refresh rates than HDMI.