Thanks for these suggestions Paul
Streetview split screen is great, but it's lot of work to get the "streetview" icon in the place you want/need it. (particularly when on a laptop with a long route, the progress slider at the top doesn't have enough resolution)
Currently, clicking on a routed section of the map does nothing, so how about use it to place the streeview icon?
Also, can the orentation of the streeview window (i.e.which direction it is facing) automatically face the direction of the route. Often, when moving the slider, streetview is looking at the path or side of the road, not the road itself.
Many thanks