You have idea, why orthographic is stretch ?! :DDD (CLICK ON CORNER RIGHT “Edit on Codepen”
You must take into account the ratio of the viewport (ie. the width/height) to update the orthographic bounds.
var zoomFactorbis = zoomFactor * 4;
var zoomFactorbis = zoomFactor * engine.getRenderWidth() / engine.getRenderHeight();
and it should work: