Chak, congrats on your new goodies! My KFL+ clones from Vape Royalty also have a fill hole too small for 18 gauge syringe tips that are usually recommended. I just use a syringe and a blunt tip needle, and it works perfectly.
Regarding rayon, I noticed something interesting in the Magma. When it's time to refill, if I open it soon after a vape, it looks like the well is empty. Then as it cools - which happens quickly - the juice in the rayon drains back into the well. I didn't notice that happening with cotton, but maybe it does the same thing. Looks like rayon wicks extra when the coil heats. If so, it helps explain why the flavor seems more intense with rayon IMO.
Another Magma note: in both of my Infinite clones the posts are off-center. One well is narrower than the other! Ack! My OCD! Anyone else notice this on an Infinite Magma clone?
When she was little, my youngest used to complain when I ground Starbucks coffee beans in the morning (I no longer drink Starbucks). She said it smelled like skunk.