The sake I had on hand was not very acidic so I decided to add three drops of lime juice. That honestly transformed the cocktail so much. It never became sour obviously but it tempered the mezcal a bit and brought forward the sake, and especially the floral components in the sake. If you have a non-acidic sake I wholeheartedly recommends adding just a couple of drops of lemon or lime.
Overall it's an incredibly well balanced cocktail. You get the sake, mezcal and Italicus in the back. You even get the lavender and bitterness on the finish from the bitters. Wonderful!
My sake was on a fuller, sweeter side, and I wish I had read your comment before…It was a wonderful concoction anyway