I run the Wagner Intercooler.
In the 2019 you can see the intake temperatures (at the intake and at the manifold) on the cluster, and display them together in the gauge view:
Cruising at 120kmh (75mph):
Intake: 7°C (45 °F), Manifold 15°C (59 °F)
WOT (few times 120-160kmh = 75-100mph):
Intake: 7°C (45 °F), Manifold 25°C (75 °F)
The manifold air temperature goes up and then remains steady.
I also did a run for about 30km (17mls) at about 180kmh (112mph), the manifold air temperature initially goes up (at WOT), then settles at just under 20°C (68 °F).
And yes, there is no speed limiter anymore (5star software). I did one acceleration to about 200kmh (125mph), that was enough for on ***** highway with such a big truck (and with 180kmh rated tires).
For now I am wondering what the situation will be when the outside temperature rises / with warmer weather.