Morning Beachers.
VG, i changed the voltage from 3.5 to 3.3 like you suggested and its still a harsh it, But im not exactly sure harsh is the correct word. I mean you can feel that its thicker then a 50/50. Theres something else going on but im having a hard time trying to explain it. Its the spring break mix from mount baker vaper which is a fruity mix.
-xICooRsYIx
I'm not sure what to suggest. Juices can be very different in the way they vape. For instance, I vape my Cinnamon Red Hots at 11W, but there are others that need only 5W or less. I got out of VW and into VV for one, and set it to 3.0V. When that was still too harsh, I set my VW down to 3W. My ZMax can do that with a range of 3W to 15W. But I had to do this because of the combination of the Juice and the Tank it was in. Other tanks didn't require such a low setting.
If your iClear has a Plastic Tube Tank (I think all of them do), this can effect the flavor, making it yucky, but not really harsh. In some Battery devices, the Ohms of the Coil will effect the vape more in the Voltage settings than the Wattage settings.
VW works by checking the Ohms of the Coil, doing some Math, and then setting the Voltage for you, to give you the approximate same vape experience as other coil's Ohms. The downfall of VW is that as the Ohms get lower, a point is reached where the Accuracy of that Voltage falls off. The Voltage may be set higher than the user would have set otherwise. The Math may be correct, but the Taste cannot be accounted for. The fact is, lower Ohms vape hotter, and Taste is subjective.
I don't know how well your iTaste V3 can set itself to a proper Voltage when set to VW with a Low Ohm Coil. There's all of this, and there's the juice itself. You may have received a bad batch, or that "spring break mix from mount baker vaper" may not perform well in your iClear. You'd have to try it in another Tank.
Another thing that can effect Taste is the difference between Single Coils and Dual Coils. Many people experience a harshness from Dual Coils, because the Ohms tend to be Low, but this may also depend on the juice.
20% PG should be more than enough to thin the VG. When making DIY with 100% VG, 20% thinning is the recommended Max. You may need to
tilt the iClear so the juice stays close to the coil. This is, IMO, a fault with top coil, long wick tanks.
Sorry, but I have no definite answer.

I don't have your devices, and I've never tried that juice.