The Saw Bench software is 100% open source. Firmware is Arduino IDE compatible and can be downloaded from our website www.tastychips.nl. You mod the code, flash your Arduino Uno and transplant the Atmel onto the Saw Bench. Updates may be done in the same fashion.
The hardware: you are free to mod stuff, but for us it makes little sense as all the units in the circuitry have been optimized for each other. It's hard to have a semi-modular system at this price point. Instead we will later on release the VCF as an Eurorack module.