SOLVED! ArcGIS Pro in fact pauses drawing immediately.
'Pause Drawing' button should stop current rendering and imediately pause. As the function works today it first renders the map and then pauses and greys out the screen. First rendering the map could make som sense if the map where then shown but as it is now the software spends a lot of computer resources to draw something with the only intent of turning of the display of said map. Considering that 'pause drawing' is intended to be used when the map is heavy or when the current scale is not the one the map is intended to be viewed in (and hence more tiersome for the software to draw) this hogs up resources that could be put to better use.