[HankB99]

I use one on a "CM4 ETHER BOARD" https://dphacks.com/cm4-ether-board-minimalist-compute-modul... which provides Ethernet, USB-C for power and micro USB for flashing an EEPROM. It doesn't have an SD card slot but it has a 2230 NVME slot on the reverse side. I program the SSD on another setup and run Home Assistant on it. Ethernet is really all the I/O needed for a small server like that.

I have another one on a Bicool Mini Base Board (A) which has a lot more I/O, albeit only one HDMI port and no USB3. It's suitable for desktop type applications with the caveat that the CM4 is barely suitable for that stuff.