I guess what I am saying is Exchange 2013 SP1 Edge Transport was a flop for "Connection Filtering"; which was the only Anti-SPAM feature that could not be implemented on any other Exchange 2013 Role Servers.
Therefore; Exchange Online Protection becomes the logical (integrated) choice for an Exchange Administrator that previously was using Microsoft Forefront Protection for Exchange on-Prem. Having done so, what is lost is true Message Tracking; that was
available in Exchange 2007/2010 on-Prem with a GUI {where Forefront Protection would have been installed } ( that ultimately can be taught to junior IT, and non-IT support technicians ).
At this point, I feel the only reason it remains not yet implemented, is that the 'noise' about it's absence isn't loud enough; and the reason it was implemented in Exchange Online Protection, is because the value is significant for MS Support Engineers
to assist their users of EOP. Now that it's in EOP; I'm staking my claim that it needs to be able to be downloaded and installed in on-Prem Exchange EAC, whether as a EOP subscriber product, an Exchange 2013 SP1 update, or other form of licensed download.
The code has been developed, and just need distributed.