I think this is the most incredible "bulk" of different "punches" of tastes I have ever encountered. Though slightly cacophonic , I am very impressed by the underlying harmony coming from so distant elements. I think the lime can also be rised to 40 rather than 30, I believe much of the pleasure comes from the sweetness of the whole egg (like egg cakes, really) and the explosive tartness of the lime.I wonder if, indeed, one might substitute the lime for an even tarter lime cordial
I would, truth be told, completely take out the syrup if I was using lime cordial instead of lime. But maybe it is worth going per stages, with perhaps half lime juice and half lime cordial, since the texture of the drink seems to be an important part and there ought to be some difference in this regard between lime and lime cordial.
Clearly, for those brave enough to try it with lime cordial (I don't have one at the moment nor can i buy it easily, as strange as it sounds), the syrup componet would have to be drastically reduced since lime cordial has a lot of sugar in it)