I was rendering a panorama but wanted to do some work while it was rendering (normally not a problem if you turn off the auto-update). In this case I wanted to move some stuff and prepare the model for a sectional floor plan: Turned off the auto-update, activated the section, did what I wanted, came back to the panorama to upload it… it’s rendered with the section in place: need to re-do the panorama.
I would expect the auto-update button to block the changes in section planes from SU if it was de-activated.
