Using iMessage exclusively with hard-wired internet

Caring for my wife who suffers from radio frequency hypersensitivities (it is a thing), I’ve created ethernet connections throughout our home, which is great for internet speed and security and allows us to turn off all device/computer cellular, Bluetooth and Wi-Fi.

This works brilliantly for email, FaceTime audio and video and WhatsApp messages, etc., but it is does not work well for iMessages, especially for sending them. It seems that iMessage requires some type of cellular or Wi-Fi connection.

I don’t want to completely abandon iMessages…

Even with my iPhone 16 Pro connected to the Internet via a USB-C to ethernet adapter, which works fine for all other Internet connectivity, iMessage seems to require that I turn on cellular in order to work.

Does anyone have suggestions?