issue with I2C on pico (initialization)

Hello,
i'm writing a simple timer using an Adafruit 7 segment display which uses I2C.
I have made a working prototype using the original kickstarted Espruino and wanted to transfer the design to the pico.
The display requires initialization which I do in an E.on('init') as well as inline:

function ledInit() {
  I2C1.setup({scl:B6, sda:B7});
  initAddr = (addr) => {
    I2C1.writeTo(addr, 0x21); // clock on
    I2C1.writeTo(addr, 0x81); // flash
    I2C1.writeTo(addr, 0xE0 | 3); // brightness 15
  };

  initAddr(0x70);
}

E.on('init', function() { //doesn't work on pico
  USB.setConsole();
  digitalPulse(LED2,1,200);
  ledInit();
}
ledInit(); //doesn't work on pico

For the pico, i changed the pins to B10 and B3
The problem is that while i'm on USB, the init works just fine. However, when I save the code and run it with a battery, the LED init fails. I later tried to call the init on BTN1 and that works fine. Something about initial power that's not working. I tried setTimeout to call it and that fails as well.
I also tried the USB.console trick and that didn't help.

setTimeout(ledInit,2000); // doesn't work
setWatch(ledInit, BTN1, { repeat: true, debounce: 50 }); // works but is less than ideal

Any ideas?
I'm running latest firmware available