One problem I had to resolve on this project was how to create a contoured thumb cluster without either splitting the pcb at the thumb transition or remaking all the keycaps. This is how I'm addressing the problem.
Because of the 3 dimensional aspect of my keyboard the thumb cluster has to bend slightly out of plane from the alpha cluster. I found that the PCB will bend slightly without any ill effects to change the plane about 9 degrees. It just needs to have some well placed supports.
The second issue has to do with easily accessing the upper thumb switches without accidentally hitting the lower ones.
As you can see, the stock ML caps are all the same profile
Interestingly enough, if the stems are broken off a cap, it will fit nicely on one of its fellows, raising it to a good height in relation to the lower row.
By rotating it 180 degrees, its profile is further improved. This placement feels really good making all 5 thumb keys very accessible.
This comparison shows the contrasting profiles. The one cap is rough because I began sanding it to remove the legend impression.
The next step is to adhere the two caps together, fill the transition flat with resin, and cast some new upper thumb caps. It should be much easier and quicker than machining some new ones.