I will highlight some differences:
Tyson is using a Teensy LC board and I am using Adruino Mega, but the code is compatible.
Tyson is using multiplexers for the buttons and the LEDs. I am not, because the Arduino Mega has plenty of I/Os to connect everything directly to the board
Tyson's program is coded nicely and professionally while mine is frankenstenized, as I am learning while I reverse-engineer pieces of code from different sources. But thanks to the tips that Tyson has kindly offered to me, now I am learning to code in a more orthodox way.
I don't like to add a single line to my code until I don't fully understand how it works. That is why the addition of new features at my development is taking so long, because I go step by step.
My knowledge still not arrives to understand 100% of Tyson's code. I can download it on my Arduino Mega, but I am not yet able to reverse-engineer the multiplexers to use my buttons/LEDs configuration. So I have ordered the multiplexers and the same display that he is using, with the intention of educating myself while playing with his code.
Currently I am working on the Analog Inputs for the use of external pedals. I still have to refine the presentation of the tuner at the screen
My next step will be to implement a touchscreen (probably a Nextion) to facilitate the personalization of switches configurations in different user layouts, etc. I am also looking for small I2C LCD's to install one individual display over each switch. Bad times for the FC-12