Yes, that will work - but only for the very, very top layer. I'm pretty sure Cura's will do it for any 'top' layer/area (IE, a space that doesn't get built upon on the next layer/layers). IE, if I was printing a ziggurat, all the flat, ceiling-facing surfaces would be ironed, not just the very top of the model.
afaik cura does it for the very top only but we have expert to confirm, I'm not really a cura user. neotko can surely say what cura does exactly and his manual is surely detailed
Yeah the problem with Cura version that the developers made it's that you can't choose the top layer that you want it, you get it on all last top layers, and that's not precise. With my method, you just need to adjust the speed and angle of the layer you want.
The main issue ATM with S3D 4.0 is that if you make a phantom process (I call them like that because they overprint, or don't on a printed area) is that if the sanding process doesn't have perimeters, S3D 4.0 doesn't print it, and that's quite problematic to control the sanding only on the inside, or with a full effect touching the previously printed perimeters. One trick to make it work on S4D is to make the nozzle size very small, that's how I though of the 2.0 version that does work on 4.0 and also you can do it without loosing print time, but ofc is less 'sanded/ironed'.
For me atm, when I need to use this I use the 3.x version, until s3d guys fix that process without perimeters don't get infill or top/bottom layers (quite weird bug, but is there). I did mail them 4 days after the release about it and after a few auto-answers I got a 'we will forward this'. The typical answers you get when you contact S3D support team (at least that has been my experience since I bough this almost 3 years ago)