My first experiment with a Frankenstein force carbonation system chucked together from homebrew kit. Found the carbonation makes a surprising difference, elevating an already very good beverage. Fun! Definitely found a more sticky rosso (i.e. punt e mes) is appropriate here
I have previously been underwhelmed with this using fresh orange or the blood orange versions. For grins and giggles tried it using a Seville orange cordial I concocted and found it to be preferable - more bracing and herbal which is to my preference. Moreover the extra sugar gives it some smoothness and body as well.
Good idea re. whiskey, works very well. Had to push the dilution a bit further than the initial shake: as you say when you hit the sweet spot the results are remarkable.