Thanks for sharing the information. The 1060 aluminum coil is definitely common in transformer windings because of its conductivity and ease of fabrication, especially for low to medium voltage designs. In some setups where heat buildup is a concern, the coil material choice goes hand in hand with cooling requirements and the type of transformer being used.
For example, when dealing with nonlinear loads, some engineers will specify K factor rated transformers to handle extra harmonic heating, but the winding material still has to maintain performance under those conditions. So the conductivity of 1060 aluminum can work well, as long as the overall design manages heat properly.
Out of curiosity, do you know if the manufacturer provides thermal performance data for the coil under higher harmonic conditions? That could be useful for engineers selecting materials for modern installations.