By some structural columns, are these all the same type, if you set to send by category, and then choose structural columns, are they still omitted?
My colleague figured out why this was happening. it seems that items that will be demolished in any phase cant be send to speckle.
And this is something you would like to be able to do?
Yes, i would say its more a bug than a feature. I also see you found the post of my colleague. So the problem is explained there in more detail with a video.