Is the idea to print planar (xy) support layers, that does have stair stepping, and then to print the final layer by either tilting the bed or by simul-stepping in {x,y} and z?
If so, it seems you'd still have quite a lot of variability in the surface because the underlying support layer is stair-stepped. But that variability would be smoothed due to it being printed continuously at the angular offset from horizontal.
That's exactly what it's doing. If you watch the video at the bottom you can see a comparison of the "smooth" print vs the normal fixed layer approach. Three things on this:
1) In general, you set the number of layers above and below the supports that you want when printing so that the variability of the support layer gets smoothed out. It seems like this should be possible here as well.
2) End products of 3D printing, especially for things like props/costumes, almost always have to be post-processed via sanding, filler epoxy, and/or primer filler paints before they're considered good enough for actual use. This process could make that post-processing step a lot faster.
3) This process is specifically for FDM printers. On an SLA/DLP printer, you would mitigate the stepping issue by lowering your layer height (layers in the example here look quite high - SLA/DLP would probably be 1/10 the height)
If you are crossing the stair steps orthogonally, or at an offset, I suppose it would be possible to dwell longer when you're over the low point of the stair step? so your motion across the offset plane would be jerky instead of smooth? thus putting more material in the low part of the stair stepped support layer, and less material on the high parts.
or if you moved the head "with the grain" you can move faster when you're on the peak of a step and slower in the valleys.
or maybe if you can place the planar ridges closely enough, you can always go "with the grain" when you are off-plane, always in the valley, and thus improve flatness. of course this requires an axis of rotation or stepping in {x,y} simultaneously.
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.
Is the idea to print planar (xy) support layers, that does have stair stepping, and then to print the final layer by either tilting the bed or by simul-stepping in {x,y} and z?
If so, it seems you'd still have quite a lot of variability in the surface because the underlying support layer is stair-stepped. But that variability would be smoothed due to it being printed continuously at the angular offset from horizontal.