It would be a nice option. There are a number of very nice programs and libraries for performing mesh operations.
The way forward is to move from the pure-Ruby importer/exporter to a more generalized compiled extension for mesh importing, exporting , and modification. There are several open libraries available which have done most of the heavy-lifting as far as mesh processing goes. They “only” need integrated into a SketchUp extension. As you know, my experimentation shows that a SketchUp stl imported based on assimp outperforms the Ruby version considerably.
Here’s a short list of interesting libraries. libigl looks very interesting.
One of the problems is getting large mesh files into SketchUp in the first place. It is common to get .stl files in the tens of megabyte range which produce .skp files in the hundreds of megabytes. The Ruby STL Importer can take a very long time to import these files.