Request for comments: Customizable image based watchface

I assume the image converter implicitly always uses the same "palette" when doing 3bpp or 4bpp images?

Yes, should do...

Does the buffer bit depth impact the performance of drawing operations?

Not much... Some will be a lot faster (8bpp?) if there's a 'fast path' implemented but on the whole they all use the same code and I don't think you'll see much difference