I finished a 60% with Matias Quiet sitches (thanks GH for all the info!). One of the main goals was to keep the case as thin as possible (which to me, seems difficult to control with alps and my poor experience) and I found silicone baking sheet is the perfect material.
It's thin and has a perfect grip. Impossible to move the keyboard once it's in place.
That's all. I thought it could be useful to share this.
