The one thing that never really worked in my brain was having multiple layers and a dedicated layer up/down key. I tend to store keys on things where I'd normally hold instead. For instance, my shift keys also hold ( and ) when I tap instead of hold. Same with control and alt. The only layer that I really use would be similar to that raise key, to turn my top row into F keys.
I really wish there was a somewhat affordable way to get good legends on keys that represent this information. I still have to take a beat to remember what | is on my keyboard every time I need it.
I'd highly recommend at least giving a smaller keyboard a go though. The kits that I've seen are fantastic if you want some hands-on tinkering, but also the prebuilt stuff is slick too. I had zero soldering experience going into it, and now it's turned into not just learning about how to use a soldering iron, but also 3D printing, as I wanted to test out a bunch of different keyboard shapes and that was a low-cost way of experimenting.