Hi Klaus, thank you very much for this interesting reply
I just witnessed what you said about " the hotspot will move slightly differently than the pano image when looking around ". In stereo/VR mode you can see that by closing one eye and looking at one hotspot while moving around. In monoscopic/2D mode there is no such drifting of hotspots. Is it an intended behavior for stereo ? Isn't it possible to stick hotspots to their backgrounds on each side ? Actually it would be like placing any stereo hotspot by hand on the left then on the right panos and sticking them there.
As for the monoscopic/2D mode I was speaking about the fact that for stereo panos, there are the image files for left and right panos separated in panos folder, and in regular 2D mode the left image files are used by default. And to me it seems that when you switch between mono/stereo modes without moving pano view, you can see that hotspots jump horizontaly relatively to the background, very much for left panos independently, very little for right ones. So there is an asymmetry. It led me to think that hotspots positions of right panos where used in mono/2D mode but on top of felt images. But I am probably confused with how it works.
I just saw also the possibility of prepared stereo-hotspot with the stereo parameter. I didn't know that before, this is very interesting, it brings the possibility to have hotspots with parallax discrepancy inside them so they can render in stereo themselves (not stay flat).
Is it also possible to have them both stereo and animated (crop animation) ? Because it should do animation crop "insde" the stereo crop. I just tried to put both arguments ('stereo' and 'do_crop_animation') in one hotspot but it just disappeared altogether.
I am also interested to know how to change the images used to compose the regular/2D modes in global stereo panos. As I said above it is by default the left side images. I would like to be abble to use right side images instead. Or even images different than left and right. Because for many stereo panos I generate actually 3 points of view, one left, one middle and one right. It is possible with circular/angular shooting, with just one camera rotating or with devices like Kandao Obsidian, Insta 360 etc. So in those cases I want to use the middle renders to display in 2d modes, because they have a sligthly better resolutions than left and right renders, due to the processing method. I think it was possible in an old verion of krpano but I forgot how. How to do that now in the last version ?
I don't know how you handle all the stereo stuffs under the hood in krpano but I imagine it is quite complex, on top of the other features. I would like to understand all those thing better but it's a shame I am still a newbie in krpano universe... I feel there is a great output potential by mastering krpano, so I will improve for sure. I have a solid knowledge now in 360 stereo photography and krpano is the only tool that I know in my short term reach that I could use to create great VR virtual tours. So a great thank you for your work Klaus. I am awaiting the next krpano update impatiently

(and I hope to have improved a little before that).
Regards
Hoel