Doesn't feel balanced to me, the Yellow Chartreuse is a bit overpowering. I think this drink would be better if it weren't trying to stick to the four equal parts motif.
3/4 oz London Dry Gin
3/4 oz Yellow Chartreuse
3/4 oz St. Germain elderflower liqueur
3/4 oz fresh lime juice
Grapefruit twist
Garnish: Luxardo cherry
Fill a cocktail shaker with ice. Add gin, Chartreuse, St. Germain, lime juice, and grapefruit twist and shake until well chilled, about 15 seconds.
Place cherry in chilled coupe glass. Double strain cocktail into glass and serve immediately.