How can I enter recovery mode (for Mac OS, on an iMac) remotely? Our team administrates several Macs. To save costs (flights, etc.) in events where we have to remotely restore a system at our client location, we are trying to understand how to enter recovery mode without being physically present at the keyboard to enter recovery mode by pressing Cmd + R.

Can I pass a flag to sudo reboot or something similar, to initiate a reboot into recovery mode?

(All of the internet searches I've done have turned up "Press this series of keys on the keyboard" to enter various flavors of recovery.)
You can set NVRAM options from command line to boot into recovery:

sudo nvram "recovery-boot-mode=unused"
sudo reboot


This will put your system into recovery mode.

NVRAM (nonvolatile random-access memory) is a small amount of memory that holds certain settings and can be accessed at boot by the Mac's firmware.