Is it safe to unplug without shutdown?

I am powering my 3D printer and AstroPrint through a wifi socket. The remote socket app offers an off timer. I’m curious whether it’s safe to just power off without shutting down through the web interface of AstroPrint?

It’s not recommended. The risk is low but there could be corruption if the device is caught writing when it loses power

Even when the printer is at idle?

Yup. Idleness does not necessarily mean that data is not being written…

Risk is low though.