A good place to start with NEW equipment CAN be checking out some youtube reviews on your new device. That can give you a starting point of what may/could work in your new equipment..
If you like what you are using now in most of your equipment there is no real NEED to change it up, but if you want to change it up, you can also ask folks here what they are using and why (that can be very important) and also try some of your own experimentation if you are bored. Thicker vs. thinner wires, spaced vs. contact, exotic, the choices are endless.
I'd suggest you leave your layercake out of this, though. The last time you discussed recoiling it, it almost ended up in the trash and you noted you were happy you only had to recoil it :"rarely."
So perhaps 5 different experimental builds for you and the layercake in a day might not be your best option.
OH and I KNOW you LOVE your dual RDAs, but seriously sometimes for just pure experimentation a single coil device might suit your purposes. It's less labor intensive, and you are also not making, installing, balancing, and then tearing out multiple builds at a time. Sometimes the simple route is JUST easier.
Anna