Working with rayon or cotton is pretty much the same as using different atomizers. All a bit different but with experience everything becomes natural.
Don't give up on rayon with the Trilogy.
I am able to use it on everything from tight Mtl to loose Dtl. From rta to rda. I prefer rayon everyday over cotton... and it's way cheaper.
Agreed, Rayon is all I have used for several years and I have yet to find a system that it can't work well in although I don't have every atty so there could be something out there that wouldn't work well. I'm not sure I would understand the physics to cotton working and rayon not working though.
I have rayon from several sources though and I can say that some work slightly different than others, similar to how cotton intended for different purposes will be slightly different, I figure this is mostly due to fiber texture and assembly layout of the final product. I find CelluCotton to be the straightest and most consistent from inch to inch for our purposes, TIDI cotton balls being the 2nd straightest but I suspect the waves from the way it was formed into a cotton ball causes it to end up being more absorbent and less transportive.
I have not caught up on this thread, so I'm not sure how much things have changed in the world of DIY rayon wicks.