I look at this from a wake turbulence perspective. As you are aware, that is what we do, measure wake turbulence for Departures and Arrivals.
There are many variables that effect the departure spacing from an ATC perspective, and many variables from the pilots perspective...
If you and the leader go straight ahead, there is no way you can use 45 seconds, that would take you into WT separation. You can mitigate this, by rotating earlier, but there is little means for ATC to require that from an aircraft.
Even with the turn, the following aircraft must watch the rotation point of the leader, if you rotate afterward, you stand a very good chance of a WV encounter before the turn. If there is a marine, inversion layer, or a headwind, even greater chance.