I’ve previously converted a Shoei MG42 to use a PolarStar Fusion Engine, but the Matrix MG42 uses a different gearbox shell with allowed most of the FE to be installed within the gearbox. The Matrix MG42 also has a microswitch installed above the trigger to allow the box mag to be activated when the trigger is pulled, so a separate MCU circuit isn’t required.
This conversion, for Justin DeLance, also included an update/repair of the drum mag. The internals of the drum mag were replaced with a MAG brand box mag mechanism. Custom 3D printed parts were used to mount both the solenoids and the box mag motor.