Considering VST3 is now a thing in Renoise, this would be an interesting feature for a “off the shelf/it just works” approach. Typically a doofer is self-contained “block box” FX DSP. You can definitely control parameters from an input perspective but it doesn’t have outputs. The reasoning is because the internal DSPs only see themselves and nothing outside of the doofer. An rather unorthodox example of a doofer that can have a signal generator.
My suggestion would be to have a built in output DSP for the doofer. From the example above the hydra hooking parameters can latch to something.