...Assuming the latest releases work OK, I think it would be better to add another table to the scirra.com/nwjs page listing all the Greenworks plugin releases available and the NW.js & Steamworks SDK versions they use, and then you can download whichever you want to work with, instead of being stuck with some fixed built-in version. So I think that would be the best we can do for officially providing the plugin....
That would be a much better solution that we have right now. Thinking about the users who don't necessary use the forum or know about this topic, you could also add some reference into the editor (like a new faded out object) that let's users know where they can download Greenworks (just like with NW.js). Or you can make bundles with the working NW.js and Greenworks plugin versions into a separate installer and create a new export option. Just thinking out loud.