Ok so here’s my suggestion: be able to load specified XRNI’s into a song without saving the entire XRNI as part of the song, and to be able to do the same for Redux. If you have an XRNI with a lot of samples, like a really big multi velocity drum kit, you have to copy the XRNI into every single song you use it in. This takes up quite a bit of space. It also means every time you hit save, it has to save the entire kit over again, so you are left waiting for it to finish saving for a while. This is something I really noticed when I started using Reaper rewired with Renoise, is how much faster Reaper performs saves when it has a ton of audio, because as long as the audio itself wasn’t edited it doesn’t have to save the audio over again.
In short, if you could use and work on XRNI’s externally, it would make dealing with large XRNI’s a bit easier.