I've made a new simulation, this time it's a simulation of the famous MXR M 133 Micro Amp Pedal.
This is the schematic I use:

and the resulting LV2 plug:

The Micro Amp is a transparent clean volume booster.
Placing it before a amp sim is useful to drive the amp harder and into more saturation.
https://github.com/brummer10/GxMicroAmp.lv2