The Fortigate article proposes that you take a profile in which your end users have said OK, I trust the Fortigate to decide what's allowed, and then you set it to not allow them to use ECH.
replyNotice that if users don't trust the Fortigate all it can do is IP layer blocks, exactly as intended.
It seems pointless to try to have a policy where people say they trust somebody else (whoever is operating that Fortigate) to override their will but also they don't want their will overridden, that's an incoherent policy, there's no technical problem there, technology can't help.
Well, yes, this is being used in corporate environments but the end user and the system admin aren't on the same page necessarily. Domain blocking doesn't make much sense in my opinion and should be a thing of the past. You already lack admin rights so what is a block on e.g. mullvad.net actually doing other than stopping someone from reading their blog? They can't install the VPN software.
replyDefense in layers makes sense, but domain blocking was never a "layer" if a hostile actor can just buy a new domain that's not on your blocklist.
I think it'd be good if ECH became more widespread so that we can get away from these antiquated control techniques that just result in frustration with no security benefits.