More than 350 DCs?

[Don Geddes (RDGURU)]

According to MDI documentation a maximum of 350 sensors is supported:

Planning your Microsoft Defender for Identity deployment | Microsoft Learn

By default, Defender for Identity supports up to 350 sensors. If you want to install more sensors, contact Defender for Identity support.

I am looking to deploy MDI in an environment that has more than 350 DCs, almost twice as many.  Has anyone ever contacted MDI support and can summarize what the options are?

[#2]

This is just a default cap (we cap almost everything...)
This allows us to be more prepared in case someone want to onbaord a crazy amount of sensors in a short time, so we can make sure they will have a smooth experience.

Simply open a support ticket, ask for a limit bump to the number you actually need with a small buffer for future use, and explain that you have nearly 700 DCs you need to deploy, explain the timeline you are planning for deployment, and you will be fine.
MDI can handle this (and a lot more in rare cases where it's needed), no problem...