I checked again with our app on Firefox and performance is not that bad. Rendering gets a slower with large SVGs, but it is still good and there is not much difference between hardware rendering enabled and disabled. So I was either wrong about slow performance on Firefox or things have improved recently.
https://bugs.chromium.org/p/chromium/issues/detail?id=114367...
This particular example is only slow on Chrome. Even if you move the edge of the shape into the viewport Firefox is much faster than Chrome. But I know from real life examples that Firefox becomes slow if handling large SVGs. I will have to investigate this and file a bug report.