It’ll be hard to do as you say. You need a support at the stern, the mast can’t be totally horizontal when plugged in the mast step (the roof is too high for that and is in the way). So you need a support which is quite high (mine is more than 2m long), high enough to not be able to reach the mast. Plus, there is a huge step between the cockpit and the roof.
What is decribed in the blog, is probably the best way to mast an Edel. Using the whisker pole is of great help !
The mast is not light, but not heavy either, I can handle it alone. I don’t know how much it weights though.