a floor can be out by 100mm. You job is to get it smooth and withing tolerance of the run out allowed for what ever the product says is allowed. Also we are not worried about level unless doing a bowling alley or something. Just smooth. BUT, the idea of the laser is to show you low and high points for you to then check to see if you can work with the dips and high points.
That would be well handy for the wood floors, always getting high spots on builders screeds that need grinding off.
