He mentioned he removed them because he was using Boba's Bounty, and also said to try it first with them all in there and remove if you need to. If you see Boba's in real life you'd know why, this stuff is thick. Just loaded some up in mine so we'll see how that goes. Was experiencing the same gurgling/flooding using a 50/50 mix with 1 flavor wick removed.
I agree to leave the heads alone using anything that is not super thick. If you're going to be hitting it like a freight train just do some dry pulls to let the wicking keep up. I've noticed for me it sometimes can't keep up with chain vaping on a 50/50 mix.
I have a Protank 2 full of Boba's and an Evod full of Gorilla Juice right now. Both BCC's have cotton flavor wicks that are about 20-30% thicker than the stock wicks that came on the coils.
All of my DIY liquids are 100% VG, and my go-to store bought liquids are from Johnson Creek's Red Oak line, which have zero PG but do include distilled water.
All of my delivery systems are bottom coil and include Evods, Protanks, MT3S, SmokTech Aro's and Kamry X10's. No problems at all. No Vivi Novas, No CE*'s and no cartos and no cartotanks.
Most of the time, genuine Kanger Evods, MT3S and Protanks with genuine Kanger coil heads work great right out of the box and don't need tinkering with. However, some variation in manufacturing might result in someone getting a coil head with a misaligned coil/wick assembly, or poorly placed or insufficient wicks. Those might need seeing to.