Hello. You are nearly a half decade too late. Any Mac with a T2 chip does not support network booting. https://support.apple.com/en-us/HT202770
While this was possible (and amazing), it is not a viable goal today unless you are using older hardware on older operating systems and you deploy and older version of server. With Mojave about to be dropped from support, this is not a wise path.
Your best option today is to enroll in Apple Business (or School if you are an EDU) Manager and deploy an MDM. Please note that additional features for T2 and ARM Macs have been announced for Monterey https://www.apple.com/macos/monterey-preview/features/, I will focus on what you can do now with existing Macs.
On Big Sur, you still need to get the OS installer delivered and then you can use the startosinstall command to initiate an --eraseinstall. Delivery and command syntax varies a bit between the supported operating systems but with an MDM you can script the fetch of the OS installer and then trigger the erase and install.
For example, on Big Sur, this will fetch the latest full Big Sur installer:
softwareupdate --fetch-full-installer
However, Catalina machines need to explicitly define the OS version required:
softwareupdate --fetch-full-installer --full-installer-version 11.6
And on Mojave, the softwareupdate command does not support fetching the OS installer so you need to fetch the InstallAssistant.pkg from the Apple CDN using something like curl and then the installer command to install the pkg.
Please note, the example below is for the 11.6 installer. If Apple releases additional full installers, then this URL will change.
curl -O http://swcdn.apple.com/content/downloads/57/38/071-97382-A_OEKYSXCO6D/97vrhncortwd3i38zfogcscagmpwksdzce/InstallAssistant.pkg
Once you have the Big Sur installer downloaded to the /Applications folder, use the startosinstall command to trigger an erase and install. WARNING - This will delete all data on the machine - WARNING. A Recovery partition and APFS is required for this to work so if you have machines that were cloned, you are out of luck.
This command will work on Intel machines:
/Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/startosinstall --agreetolicense --eraseinstall
With an MDM like Jamf, you can set this as a Self Service policy allowing a "one click" reset of the machine. Obviously, it is not instant as the OS needs to download first. However, this is effective in remote reset conditions or if you don't have technical staff.
Hope this helps find a solution.
