I like the idea of more advanced effect/filter setups. I think that they were added as they are for simplicity, to test it out. There are code comments in the original Bosca that suggest some unresolved issues, which leads me to believe there was a plan to do more with them.
That said, I can’t promise this any time soon. This kind of change would require modifications to the file format, which makes it a breaking change. So I’ll have to revisit it later when I consider the next major release (4.0).