The keyboard.io team is working on a Model-100-but-one-tented-piece, but it’s still pretty early in the development process. Obra has shown CAD screenshots on their discord!
IIRC the tenting would indeed come from the housing - it would be slight though at 5 degrees. I have a Model 100 and the sculpt itself is to try and mimic the key well design you see on the Kinesis Advantage etc and it does okay at that; I think my own Advantage is a bit more “comfy” and the pinky is more usable on it, but the M100 feels fine otherwise and I like the palm key. (I also really like having the flexibility of the split keyboard, but if you’re looking for a unibody that doesn’t matter :p)
The other big drawback with Keyboard.io’s boards is that they ship with Kaleidoscope instead of QMK/etc - not necessarily a big deal if you’re not already invested in QMK but if you are it’s something to keep in mind. QMK was ported to the Model 01 but not the 100 yet AFAIK.