You could do one in the middle of the gutter (would have to redo the gutter in that section) and paint the downspout the same color as the siding so it would visually disappear. You might be able to do a rain chain instead so it’s more of a feature. I suppose the other option would be to continue to allow it to pour off of there, but make it so where it erodes is some kind of a rock/rain garden so it doesn’t continue to erode the soil, though I wouldn’t want something like that so close to my foundation. I have also seen fancy rain downspouts where it’s shaped like animals and they’re really cool! I live on the coast, and I’ve seen them shaped like salmon, or seahorses. I’m not sure where you buy them, but I’ve seen them. I think the easiest option is the 1st.

You're going to have to have it go past that window if you want it to the left. They will need to put it as close to the top of the window as possible.

I'd consider a compromise idea to limit the visible disruption of the needed downspout. A catchment gutter up the roof even with the gables and a gutter across the top of the window to the other gutter system.