This should be a start to what you need, and someone might be willing to create a display fusion function that disables the screensaver, aswell as runs that (I tried, but failed on the toggle)
This should be the relevant code
I did come across the cmd line method and had a go at creating a couple of batch files to switch back and forth. That combined with autohotkey should make life simpler but I came across a little program called nosleep written by Mike Langford which does exactly what I need: