Ok Ive got it sort of working. I had to move all of my assets (bundled or otherwise) that I want served into a separate path to be served from a directory, /static. In my earlier setup I wanted assets served from the same endpoint as other routes, e.g.; http://my-site.com/my-image.png to http://my-site.com/static/my-image.png.
With that change in place, I updated all of my webpack config and netlify config to say that the public path was now /static and not /, and then added this to my netlify.toml redirects:
# Hack. Prevents our catch-all `app` entrypoint for paths to root, `/*` content
# from redirecting static assets like scripts or images.
[[redirects]]
from = "/static/*"
to = "/static/:splat"
status = 200
force = true
Above the normal:
# Handle redirect to main `app` entrypoint for paths to any root, `/*`, content.
[[redirects]]
from = "/*"
to = "/static/app.html"
status = 200
force = true
This is a hack from this thread: Redirect whole site to subfolder except static assets like CSS/JS - #4 by fool
I still have the issue where I must hard-reload (cmd+shift+r) to actually see any content though…