FWIW, the last breaking release of axum before this came out in Nov 2023.
I would also argue that the vast majority of axum tutorials still “work” - your app would panic at startup if using the old path capture syntax with a note that the syntax changed which should immediately get you back on track, and I wouldn’t expect the other features that were changed in a breaking manner to be used in tutorials much.
Why not larger solar panels above the electricity lines? I’ve seen some rather heavy-looking metal bars for holding up the electricity lines, maybe they could also support some panels, with minimal extra material use for mounting. Up there they would provide some shade (which should be good for the grass if there is any between the tracks, given that way too dry + hot summers are becoming the norm), and require much less cleaning to stay efficient.