@MattE STEP Import isn’t really dependent on the protocol. We look in the files for entities we support and read them. There is no difference here in 242 over 214. I did add import of point clouds to V8 but I no idea if it works, since I’ve not been able to find a STEP file that has one.
I added the ability to export to 242 last year as well. The result should be a valid AP242 file, but will only be cosmetically different from a 214 file. You should have AP242 at the bottom of the dropdown list.
I hope that we will be adding for complete support, but much of 242 that we don’t yet support will require creating new types of Rhino objects. This will be a major undertaking requiring several developers.