Ok here's a new flexible plate so far. It will work with 10x, as well as some weird 8x and 9x spacebars. It supports both 1.5x and 1.25x modifiers if you're using a 10x spacebar. Obviously the inside switch slots will be covered up by the spacebar if you're using a 10x size. Those inner switch slots next to the stabilizer slots are there if you're somehow using a 8x or 9x size, but I'm not sure if the PCB has proper spacing for the correct keycap sizes there. Those two extras switch holes are there just in case.
With this, you MUST use plate-mounted cherry stabilizers for the spacebar. Costar is not option because making the wire for it will be a pain the ass. PCB-mounted stabilizers is not an option because the PCB does not have holes there. The rest of smaller stabilizers must use PCB-mounted cherry to keep the flexibility of layouts.
^DT wiki says they're 3.5x in from the edges
Based on this 3.5x unit and cherry's 5.25" distances apart, the numbers match up to 2.625" distance from switch center to one stabilizer center, so that's how I made the plate. It should be correct. I'm still looking into the offset spacebars.
Btw "3.5x unit in" is not from the edge of the spacebar. It's from the center space between the spacebar and the adjacent key.