You could try Jim’s Ruby Toolbar. It allows you to select a Ruby file to load and reload it (after edits) by clicking a single button. Not as nice as if NetBeans had a command to do it, but much easier than cut-n-paste in the Ruby Console!
http://sketchucation.com/plugin/1632-ruby_toolbar
I think that all of NetBeans is programmed in Java. I wondered how plugins are written because I wanted to see if it would be possible to add “folds” in the editor for more kinds of code (as is, it only does modules, classes, and defs - no if statements, code blocks, etc. I suppose it is out there somewhere, but I couldn’t find clear enough documentation to even get started…
I agree that would be very nice. I don’t know the technical explanation, but for whatever reason that isn’t how the hook for the debugger is implemented, so no IDE can overcome it. The view is frozen until the debugger lets SketchUp’s main loop start running again.