Nuge Sorry for not answering instantly. As a software developer I try to invest more time in improving the software than in customer communication.
Let's take a look how the material editor for the SketchUp plugin came to life: Enscape for SketchUp was officially released in May 2017 (version 2.0), with some kind of a beta phase since March (version 1.9.6). At that time only the Revit plugin supported the full potential of our materials. SketchUp had only very basic materials, even less than ArchiCAD has today - Albedo texture with keywords for specific reflectivity settings and for special materials like water. Of course, many users wanted more control ("Look at what the Revit plugin can do!"), and they were right. But it's also wrong to say, that the SketchUp plugin was useless without it.
In December 2017 (after a short closed beta) the material editor was released in preview versions, followed by the official release in March 2018 (version 2.2).
Of course we could have adjusted our priorities to release the material editor earlier, but that wouldn't be fair to our existing customers using Revit. So we happened to implement area lights, the presentation mode and many other small improvements, before investing huge amounts of time into the material editor for SketchUp. There have been many SketchUp users complaining about it, but I still think it was the right decision.
Today we face the same dilemma. Prioritizing feature requests is never easy. We decided to work on two topics that are highly requested and can benefit most of our users. You can find them on trello, the board is still regularly updated and read. We also wanted to include a material editor for Rhino in the next release, but postponed it because of bugs on the McNeel side. Believe me, we are not happy about it. Rhino users have to live without proper material support since November 2017.
At the moment we try to release every 3-4 month, meaning version 2.4 should be released in September/October. Then we'll decide what to do next. If we schedule this topic for the 2.5 version, this means a release in Q1 2019, probably a preview in late 2018. I don't want to make any promises. Besides better material support for ArchiCAD there are a few topics on our agenda, that are highly requested, just take a look at the Trello board. You should know, that we are aiming for feature parity between all plugins, and that is a strong argument for providing better materials in Rhino and ArchiCAD.
Short summary: This topic is not yet scheduled, but we are trying our best to bring it to you as soon as possible.