Did someone try pisound with the Automatonism Pd-based system designed around modular synthesis? It uses Pd-Vanilla, so there isn’t really a reason for it not to work. But it’s always good to make sure.
Don’t know about others but it really got me to understand Pure Data in a new way. It includes dozens of pre-programmed modules which can be connected with one another without thinking about control vs. signal rate or even hot and cold inlets. The site includes a couple of “synth recipes” which make it remarkably easy to get started. It has a rather powerful state-saving system which allows to “morph” between different “presets”. Could work remarkably well with a headless Pi+pisound.
Also, its main patch is called main.pd so pisound might even work directly by plugging a USB key containing it.
If it does work well, it might be a good idea to add an example to the repository of tested patches.