FxPlug 4 How do I force a render in the active project?

You can change a parameter value. Some developers will add a hidden checkbox they can toggle, or add a hidden integer parameter they can increment. It's probably better to use something like an integer parameter since a checkbox will end up being hashed to its previous values every time its toggled.

Normally, if you change any parameters at all, the host should notice the change and re-render. So the question is, what are you doing that isn't causing the host to notice something changed? Perhaps whatever is changing should be somehow tied into a custom parameter?