Hi,
laus, please add preload to hotspots. I trust it is easy enough.
The preload feature is everything but not easy!

It's a very special edge-case out of the normal internal workflow. If possible I would recommend not using it - normal loading has the advantages of unblocked and parallel loading. Then using preload then everything is waiting until the preloaded file has finished loading.
If you're using scenes in your xml you could put the 'preload' hotspot out of the <scene> elements, add keep=true to it and load the first scene in the onloaded event of the hotspot. The result would be the same.
Best regards,
Klaus