While our company nowhere as big as yours, are we are taking this T2 chip opportunity to enable and support our network team's investigate why Internet Recovery is so slow. If you want to support Apple computers your/our/everyone's network has to support Internet Recovery. We have to play by Apple rules
PS...After my enabling plan fails : ) best solution we could come up with, for slow networks... is a scripted "startosinstall"
We have macOS "server' (the old netboot servers) machines on the same switch as where the onsite staff image we are just going to copy a the full installer and the "startosinstall" script to each machine inside one folder. The onsite team will then copy that folder to the root of the machine they need to do a clean install on.... It's more clicks and more dragging but it's about the same time as OS netinstall.
Starting point for the "startosinstall" script https://www.jamf.com/blog/reinstall-a-clean-macos-with-one-button/
This is how I have done all my Mojave testing ....
you're going to wanna hide the mojave installer on the computer. then, use the starttoinstall -eraseinstall flag on any computer that comes back to you in the future to quickly delete the current os and install a clean new oem mojave without any need to download the installer. also, make a dep prestage enrollment to pull everything down upon first boot