SVG & hotspots optimisation

[Big Rinch]

Imagine that you are standing in the middle of a garden, and you need to highlight all the insects around you. If one place has several insects, you need to draw a polygon to cover all of them. 

We put SVG over a panorama image using hotspots. And it works great if there is a small number of polygons, but when there are tens of them, rotating the panorama produces blinks, and some polygons can disappear altogether. Any idea how to fix it? 

Maybe Marzipano is not a good choice for our situation?