I’ve only made one hand wired board, a 50 key flat, one piece ortho, but I learned some good lessons.

First, the mental hurdle for me with soldering was that you’re not JUST melting the solder, nor are you trying to get the components’ leads hot enough to melt the solder, which might fry them anyway. Instead, heating the wires or leads makes them attract solder when you melt it with the iron. Once I watched enough videos to make that jump and to see how it’s done, I went from hopeless to mediocre, and mediocre is good enough to make a keyboard. Maybe I’m just thick, but my general takeaway is that anyone can learn this.

Second, most MCUs have the port on them already. Unless you were talking about having the two halves not connect to each other, then there’s no component or labor savings in going wireless. I also was able to use KMK on a pi pico for my MCU, which was a godsend for me as someone who doesn’t code in any meaningful way.

Finally, If there’s any way your plate (maybe more of a “bowl” for a manuform, lol) and case can physically support it, consider soldering to Kailh hot swap sockets rather than switches. My little “Planck+3” board is not true hot swap, but it should be no-solder swap if I want to change the switches.