My first “weird” mechanical keyboard was an early Planck version (I was trying to learn steno and it was a fairly cheap NKRO option). I ended up getting rid of it as I had trouble adapting to the layout and layers. I didn’t end up pursuing steno very far, but it was a good learning experience.
My first ergo split was much more recent with the Ergo travel that I was able to find very cheap on mechmarket. I still had to build it, but it was a good learning experience and forced me to learn more about flashing firmware, soldering, and the details of keyboard construction.
I’m now using a Draculad wireless after really learning Colemak dhk on a 34 key dilemma, both of which I really love. I don’t think I would be as comfortable with firmware and switching to zmk for the Draculad if I hadn’t had the experience getting zmk to work.
I’ve been happy to experience many years of custom keyboards and the advancements in firmware over that time, and I think I’ve found an end game solution with zmk/Draculad
Others have mentioned some of the boards on this list, but YAL should be pretty comprehensive list of boards with dpads