The only thing I could really use, and I don't know if the Eclipse plugin even does this, is keep track of dependencies, for instance, if I want to move a piece of code to a new project, then all the dependant code could come along with it, and a few other things like that (select a function, press a key to see calling functions and dependent functions...). Those would be real time savers if it supports that functionality or similar.
I installed the only thing I see at the specified update site, with or without Group by Category enabled. It's Brightscript Core version 184.108.40.206108031520. I was able to convert my project to a Brightscript project; but other than folding and highlighting in the editor, I don't see how to access any of the other capabilities discussed in this thread. And as I mentioned, I'm getting error markers in Brightscrpt code that's been running fine for months.