walterbell • yesterday at 7:37 PM

  You can already do that?
  Apple offers that to all customers who open up an enterprise account and direct billing line

What's the name of the feature for Apple Enterprise customers that would allow iOS 18 to be installed on a newly provisioned device today?

Downgrades are not supported by Apple Business Manager MDM and there's no reference to downgrades on the Enterprise page, https://www.apple.com/business/enterprise/