Timeout on I2C Write BUSY - not all the time [Adafruit 8x8 matrix backpack]

@Robin

i tried in a dirty way by adding some time in each command (a blank loop) and a try catch.
i've got less error.
sometime (1 in 5 switch on) there is no error but display does not start.
When i unplug/plug i lost the connexion therefore i do not receive the error... but i blink the led in the main program and it blink....
show you my ugly code

const onInit = function() {
  clearInterval();
  clearWatch();
  pinMode(B6, 'opendrain');
  pinMode(B7, 'opendrain');
  require("Font4x6").add(Graphics);
  /* rajouter les init de connexion pour le display */
  console.log("init programme affichage matrice v2.2 - éric choisy ©2019");
  console.log("mém. utilisée: "+Math.round(process.memory().usage/proc­ess.memory().total*100)+"%");
  // initialisation I2C

    console.log("setup I2C");
  I2C1.setup({scl: B6,sda: B7});
  // rouge
  try {
    console.log("try OSC ON");
    I2C1.writeTo(0x70, 0x21); // turn on oscillator
  } catch(e) {
    I2C1.setup({scl: B6,sda: B7});
    setTimeout(function() {
      console.log("try again 0x21");
      try {
        I2C1.writeTo(0x70, 0x21); // turn on oscillator
      } catch(e) {
        console.log("does not init",e);
      }
    }, 250);
  }

  // init suite I2C
  for (var i=0; i<10000; i++) {
    //
  }
  try {
    console.log("try display ON");
    I2C1.writeTo(0x70, 0x81); // display on
  } catch(r) {
    digitalPulse(LED1,1,20); //rouge
    for (i=0; i<10000; i++) {
      //
    }
    console.log("try again display ON");
    I2C1.writeTo(0x70, 0x81); // display on
  }
  digitalPulse(LED2,1,20);//verte
  try {
    console.log("try brightness");
    I2C1.writeTo(0x70, 0xE0 | 0); // luminosité 0-15
  } catch(r) {
    digitalPulse(LED1,1,20); //rouge
    for (i=0; i<10000; i++) {
      //
    }
    console.log("try again brightness");
    I2C1.writeTo(0x70, 0xE0 | 0); // luminosité 0-15
  }
  digitalPulse(LED2,1,20);//verte
  setTimeout(envoieMatrice, 1000);
};