I don't think it is either, but then again neither is honest, direct, communication about what's going on with product development.
It seems that for the past two years they've been putting all of there eggs in the "save it for V5" basket. Ironing was one of the first reasons I switched to supermerill's fork of Slic3r, formally called Slic3r++ and now called SuperSlicer. It's not as pretty as S3D, and Slic3r's support material generation downright sucks compared to S3D's, but it also has VERY active development and is updated constantly with new features and bugfixes.
Here's hoping a new version of S3D is actually released soon, and that ironing is part of it.