So I've got a new revision of the Super Nintendo sound chip emulation code from antires, and after modifying a few parts of my own code the GStreamer plugin is now working.
Reliably. No more magic, no more crazy kludges. Feels good.
I think that the filter development branch is ready to be merged into the mainline, which means that the typefind code is next to be written. Being in deep hack mode is damned refreshing.