phew. Look at me (hopefully) reviving this thread hahaha
It's rather annoying to me that the "automatically joins to walls" category parameter isn't available for structural columns. There are many times that this parameter would be useful for structural concrete columns (columns in walls, shear wall zones, geometry definition in plan). The only work around I've had is to place a concrete column and have it slightly engage with a concrete wall, unjoin the concrete column geometry instance, then move the column where it needs to be. However, if I have a wall thickness transition on an upper level, the column continues to automatically join, and I go through the process again, and have to repeat for the other levels. A workaround that I've had to do is create a structural column that is a steel material (for shear wall zones and columns in concrete walls) so it doesn't automatically join. I create concrete column schedules based on elements in the model, so if I use the "steel material" concrete column and I need to update the size, I unfortunately have to update the actual concrete column that can host rebar then update the "steel material" column.
I can't see an integrated workaround so that structural columns don't automatically join, even in R2022.