Based on the recipe, I made one of these with Liber's Pineapple Gum Syrup, rather than the pineapple juice discussed in several of the comments. I thought I was a very nice after-dinner drink, with the Fernet herbals winning out over the Chartreuse.
Little late to the party on this one, but I'm guessing the recipe has been updated, since the comments reference a lack of lime juice--now listed at 3/4oz--and using pineapple juice instead of the now listed pineapple syrup. Made too much of a caramelized sous vide pineapple syrup recently (juiced caramelized pineapple chunks, and cooked that with equal parts demerara sugar and the pineapple rinds for 2 hours at 135 degrees) and was searching for recipes to use it up. Made this for myself and 3 other jaded bartenders, and we all loved it. Very balanced given the ingredients list, with both the Fernet menthol, minty goodness and Green Chartreuse herbal elements peaking through but not dominating. 5 stars.