What do I need for my custom MIDI controller setup?

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(sorry for necroposting or whatever it's called, I just realllly wanna talk about this specific project)

Yo, this is definitely a diy lumatone replacement right? I'm actually in almost the exact same situation as I wanna build a big isomorphic keyboard with analog keyswitches

The way I would approach the massive amount of analog keys is by connecting the columns of the button matrix onto a chain of parallel-out shift registers, and the rows into an analog multiplexer. This should work (in theory, haven't tested yet), as only one switch is a part of a closed circuit at a time, so the shift register(s) shouldn't get fried by too much current

I wrote some "dummy" code to test the theoretical polling speed by executing the digitalWrite's and analogRead's as if I was polling the keyswitches and I got a polling rate of 250000/s??? (that can't be right)

int rows = 8*4;
int columns = 8;
int state;
long time;
long finaltime;

void setup() {
  Serial.begin(9600);
}

void loop() {
  time = micros();
  for (int r = 0; r < 10000, r++;) { // testing how long it takes to poll the switches 10000 times
    read();
  }
  finaltime = micros() - time;
  Serial.println(finaltime);
}

void read() {
  for (int j = 0; j < columns, j++;) {
    digitalWrite(2, random(1)); // "selecting" the multiplexer row
    digitalWrite(3, random(1));
    digitalWrite(4, random(1));
    for (int i = 0; i < rows, i++;) {
      digitalWrite(5, "HIGH"); // pulsing the relevant shift register pins
      digitalWrite(5, "LOW");
      digitalWrite(6, "HIGH");
      digitalWrite(6, "LOW");
      state = analogRead(A0);
    }
  }
}

Also @fuzzybeverage I would really love to chat with you as our projects are so similar we could offer advice to each other (also MICROTONES!!!1!!)