It shouldn't really be necessary to do this. In normal printing, infill can have gaps of several millimeters and the final surface will still look smooth if it

It shouldn't really be necessary to do this. In normal printing, infill can have gaps of several millimeters and the final surface will still look smooth if it's flat. The plastic essentially bridges the gap before hardening, and over successive layers the imperfections are averaged out. The same thing should happen when moving in both X/Y and Z like this - the first layer will be non-perfect, but if you do 3-4 layers it should end up fairly smooth.