This recipe is light on elderflower liqueur to make a relatively dry drink. Those after a sweeter version may prefer to follow the standard 3:2:1 Spritz...
This drink is also getting very famous in France and Belgium. Sweet, can be "switched", I mean you can use, prosecco, champagne; sparkling wine.... Elderflower syrup to make it less alcoholic, I am pretty sure you can make it virgin with alcohol free champagne. For the taste; not sure it would be worth it
This is indeed popular all over Switzerland, when I arrived here in 2012 I had no idea. Have had a lot of them since then, nice in the few months of warm weather we have here on a nice terrace :P We just had one here in Ticino, though the terrace is still freezing haha.