I think that is something interesting to avoid a loop between two abstractions, but without using the send~ and receive~ objets.

The reason, is far more intuitive to use the first form while trying to synthesize a sound in a modular synthesizer.

Like this:

[abstraction 1~]<-------[abstraction 2~]

Instead of:

[receive 2~]
[abstraction 1~]
[send 1~]

[receive 1~]
[abstraction 2~]
[send 2~]

Is pretty cool to make an abstraction with one inlet, one send, one receive and one outlet, in this order, but dont works. ;-(