Fwiw, and probably a little more on topic: I'd wish there were parallel inserts.
As a simple example: I like using speaker impulses for recorded guitar signals ... Now, placing a single IR via Space Designer isn't an issue at all, just the usual insert job. But what if I like to mix several speaker/mic combinations? Right, I either have to copy the track (not exactly a comfortable solution) or use (pre fader) sends, entirely lowered down audio faders and multiple busses (even less comfortable). With parallel inserts, the entire thing would be a no-brainer.
Another option would be something like Peak Pro's "VBox" (TC Works had one for Spark back in the day as well) that gives you a plug-in routing matrix as an insert.
Is there any AU out there right now that does that? I can't think of any, but I'm not sure...