Wiring for controling power comsumption on a socket in the middle of a paralel set of 3 sockets

Did not discover any fault in the sketch!

Sure? Shouldn‘t there be a connection from „L“ to „SW“?

jmpnm will surely configure the Shelly plus 1PM with „auto on“! If the relay is activated via an external command or „auto on“, an activation by wire would be obsolete. But it will not harm anybody to add the wire between SW and L…

Although the Shelly1pm is rated for 16A (and I assume your circuit is protected by a 16A circuit breaker), I would avoid to "daisy chain" socket no3 after the Shelly1pm.

You need to keep in mind that - according your diagram - the full current which is drawn by socket no3 flows across the terminals (and the electronic board) of the Shelly1pm.

Basically, that should be feasible (in particular when the load on socket no3 is low), however I would not unnecessarily run the current from socket no3 through the Shelly.

Better you modify you circuit and monitor with the Shelly the power from the last socket outlet (no3), or you add some additional WAGO terminals.