That's probably the acidic tang from the kiwi/apple at work enhancing the TH (through throat irritation). Myself I can't do melon for long so I don't really ADV the stuff.
Similarly the TH on Sour Candy due to the lime.
So yeah, if you're looking pure TH, those two (and the other sour flavors, the controversial POG included) probably fare a tad better them LF, as mentioned.
LF doesn't fall behind that bad though, as I personally think that while the sour flavors hit harder, the LF TH is a whole lot smoother in the long run. Hence probably why I can ADV LF for nearly a year now, and yet I can only run a few tanks straight of Sour Candy before having to switch back (not sure if this applies to Green Blast though coz MELONS = Nope).
YMMV ler, as my built is probably diff from yours (or anyone else's).
However, this entire discussion does bring to fore the important fact that TH is actually not just a Nic thing, flavoring choices do effect it too - so keep that in mind whilst selecting juices.
Plus, this means that you'll probably NEED to go physically test these juices first to be completely sure of what particular juice is best suited for you IMHO, both TH-wise and taste wise.
Tried a few LF , POG , AP , Melon ?, Sour candy And some forgot the name. TH is a bit weak compared to what i am vaping now ( DF Athena & 50/50 Fruit Punch. They only have 6MG for tester . Not dare to take on the 12MG because most of the US brand 12 MG is too strong for me.
Missed out the Green Blast omg. I just took the bottle and sniff the flavor directly and not really like it. Perhaps have to go once again lol