Most of those offerings are VST plugins. Which most likely means you need to be running programs that accept the plug-ins. These programs tend to be recording/editing programs (I have used a few of them in the past for recording purposes.)
You could probably use one of these programs to "save" files that have been processed and then move the resulting file to the StreamPlayer. That way, you wouldn't need to have it running on the StreamPlayer itself.
I notice they do have a Linux program as well (Stereo Tool), but it appears that it requires a graphical user interface and the StreamPlayer has none.
A version of the StreamPlayer could be built with something like Ubuntu Linux with Jack installed, but this would be a completely different platform.
So, yes, it could be done. But it is not something we could add to the standard StreamPlayer and probably wouldn't want to offer it as an "official" product.