As you know, we have been following up this Datapath Service Set issue via other channels, but I add a comment here in the forum as well as it might be of interest to others.
The short version is that this is not a new use case for us. A uniform DPSS API is important for us for all of our targeted platforms, including IOS-XE and ISR-G2. We need support for inject/copy/divert for both L2 and L3 directly via a specific interface. In other words, where the onep application determines the interface to use for each L2 frame or L3 packet.