A few developers (including myself) have thought about a platform for prototyping modular DSP algorithms.
There are many scripting languages for audio DSP such as Faust, SuperCollider, Csound, ChucK, or Vult that would be ideal for interpreting and running in a Rack module.
But also many generic fast languages like LuaJIT and Python with Scipy, which is only fast when processing blocks of audio but basically has the power of MATLAB.
Frank Buss Formula exists, but I don’t consider it to be a prototyping platform for implementing advanced DSP algorithms and analog modeling, rather a tool for users to implement functions that aren’t available as modules.
Does this idea interest any plugin developers? The UI could simply load a script and watch it for changes. It could have some knobs, switches, inputs, outputs, and RGB LEDs that would be exposed as variables in the scripting language.