Next experience: today I tried Havana 3yo instead of Bacardi. It works, but changes the taste and one has to up Chartreuse and reduce Agave syrup. Grapefruit twist is fine, especially if you rub the edge of the glass after twisting. The bitters I would still reduce to half.
Redoing this cocktail, I tried to be cautious with the bitters and change the grapefruit twist for a lime twist. Maybe a good solution for sweeter tooth.