Is there a way to add or modify panoramas in a panorama set that is already uploaded to the twincloud? or do I have to render the whole set again?

When I try to add another panorama to a panorama set already uploaded to the cloud, the engine will start rendering the whole thing again, im wondering if there is another way to just integrate the new panorama to the whole uploaded set

You have to re-export the whole sequence.
The rendering time will depend on you rendering engine. what are you using?