Maybe a completely different approach would be needed here that doesn't use hotspots.
I think multi-resolution panoramas will become more and more important. On the one hand, we have increasing camera resolutions and, a more recent trend, high pixel densities for desktop monitors (retina displays). On the other hand, we have mobile devices with small screens and limited bandwidths. Multi-resolution panoramas are what's needed to bridge that gap, so it would be great if they offered the same features as single resolution panoramas.