If we are in our home grounds, I already have a bunch of routes on our chart plotters.

Before a long passage, or one with some "bail outs" for weather, etc I tend to preplan alternate courses. This is especially the case where fog or nasty weather is the case.

Our nav systems make that convenient. I have found that a PC with a mouse and keyboard is easier than using the UI for a chart plotter display. Also, If we upload from a PC, the waypoints are fewer because you reuse the same waypoint and the display is less cluttered.

If you back these up on a PC, then if you have a voltage or other crash, you can resurrect you old work. Sometimes, with a firmware upgrade, you will lose you work otherwise.