What are you planning with the “Moving bed!” update to the FABkit?
PS: Too bad the kickstarter didn’t get through, but nice to see you have a plan B.
Wait and see my friend 
Ok I see it now - the bed moves up and down instead of the head. But you still have the height sensor that might interfere with the material if it’s warped a bit for example?
its the same system currently employed in the fab40 and 100 it has not proven an issue, if the material is warped to the point its touching the sensor it will be hitting the nozzle too. The sensor is positioned only slight below the nozzel.
Another nice feature of the new bed is you should be able to attach low profile clamps to help hold down the material, or just normal tape 