I feel like one RDA everyone forgot about was the Immortalizer RDA. If anyone's ever tried it, the flavor on that is unparalleled. Only issue was that since it had no juice well, it would gurgle like old style atties when over-dripped. I think a big part to the flavor came from the bottom airflow and the side post walls. This forms a small chamber for the coil to sit in, and it forces the air to travel around the entire coil.

A few things tweaked here and there would greatly improve this rda. I would choose posts similar to the Kanger Subtank Mini RDA. It's wider plus the channels for the leads to sit in provide a much more solid connection without the worry about clipping the wires. This is especially important if anyone is working with nickel wire. I only vape on nickel wire now, so there are only a handful of RDA's I can actually build on consistently(Veritas, and Marquis mainly). Everything else either clips my leads whenever I try to tighten down the posts, or the connection isn't strong enough. This leads to wrong temperature readings.

Also would change out the aluminum for stainless steel, and make the top cap domed. Make sure the insulator separating the positive post is a fair distance from the coil. Dry burning surpasses the melting point of even PEEK insulators. Add in a juice well and you've got yourself the perfect single coil flavor atty.

Some people may be against the idea of not having the standard dual coil option. I'm a single coil guy and don't care for an option for dual coils. A lot of people I know mainly build single coil. It is just more consistent with every build. Don't have to worry if both coils are firing at the same rate. Only times I find myself going for dual coils is when I'm trying to cloud chase(which I find myself hardly ever doing when a single coil can already put out satisfying clouds).

TLDR; Immortalizer RDA mating with a Kanger Subtank Mini RDA to make the perfect single coil flavor atty (maybe make room on the posts to have vertically stacked dual coils)