LAN, always lan if you have the option.
There’s practically zero difference in setup complexity vs Usb. One uses an IP, while the other uses a serial path.
Other than that, LAN provides multiple advantages over usb:
- Can be located centrally in the house without requiring the server to be moved.
- Avoids Usb3 interference issues.
- Avoids the usb path changing (when not using serial by id paths)
- Avoids having to pass through the usb device once you switch to Proxmox.
I switched to proxmox a few years ago and had a lan coordinator. Didn’t have to do anything beyond loading a backup to switch. ZigBee wasn’t affected at all.