Supercruise just needs to accelerate a bit faster in the initial phase, there's a lot of dead time on trips to the edge of a system. It slows down really quickly, but speeds up really slowly regardless of the proximity of stars/planets/gravity wells. The physics is wonky.. objects in space take just as long to speed up as they do to slow down. If supercruise acceleration was sped up maybe 30% I reckon most of these moans would go away since it would shave maybe a minute or so off the longer journeys.
The physics is wonky?
What is the last time you travelled at faster than the speed of light around a remote solar system trying to dock at an orbital space station?