Issues when trying to backport changes to drimage

I made a first attempt to integrate the changes from this module back to drimage and ran into a few issues.
Just wanted to have you thoughts/input on my findings before I try to continue.

1/ when not using image_widget_crop nor focal_point the width/height is not calculated correctly: (DrimageSubscriber.php: 123-126)
Original:

      else {
        $width = $style_parts[2];
        $height = $style_parts[3];
      }

Changed to make it work:

      else {
        $width = $style_parts[1];
        $height = $style_parts[2];
      }

2/ Images with a space in them are never found (%20 in URL)
The image styles are correctly created and styled images are put there, but the keep giving 404 / not found. Also with direct URL's. (might be an issue on our end, still unsure)

3/ Sometimes random images give a 404 on some devices, not on others... Haven't been able to pinpoint what causes this. Be interesting to know if you have experienced this?