3 monitors via back Thunderbolts 4 2K @ 100hz

Please provide the exact year model of the Mac mini that you have.

see > Identify your Mac mini model - Apple Support

For additional information on connecting displays to the Mac mini's.

see > Connect a display to Mac mini - Apple Support

Your welcome.

You may be able to run all three of those LG 29WQ500-B displays on USB-C to DisplayPort cables.

If not, then run two on USB-C to DisplayPort cables and one on an HDMI to HDMI cable.

See "Display Support" at > Mac mini (2024) - Tech Specs - Apple Support

Apple M4 chip

Simultaneously supports up to three displays:

• Up to three displays: Two displays with up to 6K resolution at 60Hz over Thunderbolt and one display with up to 5K resolution at 60Hz over Thunderbolt or 4K resolution at 60Hz over HDMI
• Up to two displays: One display with up to 5K resolution at 60Hz over Thunderbolt and one display with up to 8K resolution at 60Hz or 4K resolution at 240Hz over Thunderbolt or HDMI

Thunderbolt 4 digital video output

• Support for native DisplayPort 1.4 output over USB-C

And for M4 Mac mini >Connect a display to Mac mini - Apple Support

For Mac mini with Apple M4, you can connect up to three displays in the following configurations:

• Connect up to three displays, two with up to 6K resolution at 60 Hz over Thunderbolt, and one with up to 5K resolution at 60 Hz over Thunderbolt or 4K resolution at 60 Hz over HDMI.

• Connect up to two displays, one with up to 5K resolution at 60 Hz over Thunderbolt, and one with up to 8K resolution at 60 Hz or 4K resolution at 240 Hz over Thunderbolt or HDMI.