The full name of these laptops is T14 gen x or T16 gen x. Each generation has a different motherboard and other hardware. Some have Intel CPU, some are AMD.
Lenovo makes a USB-c to Ethernet converter that works in ArcaOS. The USB-c to DisplayPort also works in ArcaOS. You cannot have both plugged in at the same time, because only one USB-c port actually works with these converters. The USB-c dock is not fully work under ArcaOS. Many T14 models have built-in Ethernet ports that work just fine with no converter.
System Information:
Manufacturer: LENOVO
Product Name: 21AHCTO1WW
Version: ThinkPad T14 Gen 3
Physical memory: 2.21 GiB
Available memory: 2.17 GiB
The early T14 and other Lenovo computers have poor VESA support that is corrected in later models. This only is a problem with external monitors. DisplayPort worked better than HDMI in early models.