I love my keyboard.io Model 01 keyboard. Except I don't particularly love the "spider" stands that came with it - they lift the keyboard up a bit too high and are generally hard to adjust to fit to the ideal tilt for my wrists.
So I made these minimal wedges that fit under the keyboard as a replacement, using the thumbscrews that came with the keyboard and a little bit of hot glue.
The design is customizable with the amount of tilt; the default value of 15 matches the included spider stands. This makes it usable with the tented center support, should you want to use that, although in retrospect it would be easier to simply put a 2cm-tall block of wood + rubber feet under it (perhaps attaching that to the center bar with hot glue).
This file only generates a single wedge, in case you want them to tent differently for some reason. You'll need to print one for each keyboard half. I am able to fit both wedges within a single print on my MakerBot Replicator Dual but your mileage may vary.
Hot glue is versatile
Use some hot glue to make some little rubber feet for it. I recommend putting a few thin lines on the backside to prevent it from spinning around (especially near the thru-hole for the thumbscrew) and some larger dollops on the three feet; these will be your actual support for the keyboard.
Leveling the feet can be a bit tricky. One way that works well is to use the heated tip of the glue gun to reshape whichever foot sticks out the most. Another approach is to attach the feet to the keyboard before adding the feet, then when it's mostly cooled down but still a bit soft, put the keyboard right-side up atop some thin paper (such as newsprint) and press it down to shape the feet. Then you can carefully peel the paper away from the glue and hopefully it's all shaped right!
Using the glue gun to reshape the foot