Question to our users about controllers

[Amm0]

========== NEW QUESTION ==========
Thank you all for input. New question. What specific features would you like to provision in these controller type of setups. What is your #1 use case, which config is most often needed to apply “en masse” or to multiple devices?

Perhaps, controlling “device-mode” settings without a site visit?

That one that’s not workaround by Dude or some foreach ssh ....