Hey mate,
This is going to be kind of a drag, but I think two things are going on:
1. iClear30s are fine in a lot of use cases, but they don't handle high-VG eliquids very well at all due to being top fed and such. This isn't a knock, as a protank or such won't handle the eliquid you're using well either, as I believe it's around 75% Palm VG. I generally don't recommend going over 50/50 with them, and something like 70/30 will work way better (for reference, you're trying to use 25/75).
2. The istick simply can't put out a low voltage, and it lies when it says it is. It's 3.3V is actually 4V. You have to reach an equilibrium between how fast the coils can wick in new VG and how fast it'll get vaporized, or you'll get that harsh dry awful flavor.
I think your best bet would be to thin the high-VG eliquid with some unflavored PG. You can try to thin it out with some distilled water and/or vodka while taking lots of primer puffs and swirling it upside down to keep things coated, but you have a looooot to thin out.