i watched the video.........
https://www.youtube.com/watch?v=rpZdQrvLYCwthey packed the column with copper scrubbies/mesh and insulated the column, both good ideas.
i have a solid piece of neoprene pipe insulation i pull over over my 2" column.
i believe 100% copper scrubbies can be hard to find, but i use copper mesh.
a 500gm roll of mesh, 100mm wide mesh, is about 9m long.
cut the 9m into 4 x 2.25m lengths, rolled up, these 2.25m lengths fit tightly into my 2" column (but not too tight obv)
don't worry too much about temps, you do not control them.
worry more about the distillate output speed by using the power controller.