We could use:
https://github.com/mozilla/pdf.js/blob/c3d08580627471432a6ad0b2fdb948df64126afa/src/display/api.js#L929

and look at bit 4.

The following pdf:
https://orimi.com/pdf-test.pdf
is not editable in neither Acrobat nor Edge nor Foxit and nor Okular.
return (
      newScale === this._currentScale ||
      Math.abs(newScale - this._currentScale) < 1e-15
    );
  }
  _setScaleUpdatePages(newScale, newValue, noScroll = false, preset = false) {