I wish there was a function to copy and paste a selection of Elements (either in plan or in 3D) to another layer.
Say you would copy Elements either in 2D or 3D and then in the Edit menu, you would have a new option for "Paste Special", where you could choose where (to which layer or to a new layer) you want to paste your Elements from your clipboard.
Each Element has an information about its Home Story and Layer so making a copy of the same Element on the same Home Story just on a different Layer can't be that hard to implement. With some layer management, this could even be used as a workaround for the missing function of copying Elements in 3D, which is supposedly not so easy to implement in Archicad.
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