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.
this._currentScaleValue = newValue.toString();
    if (this.#isSameScale(newScale)) {
      if (preset) {
        this.eventBus.dispatch("scalechanging", {
          source: this,
          scale: newScale,
          presetValue: newValue,
        });
      }
      return;
    }
    docStyle.setProperty(
      "--scale-factor",
      newScale * PixelsPerInch.PDF_TO_CSS_UNITS
    );
    const updateArgs = { scale: newScale };
    for (const pageView of this._pages) {
      pageView.update(updateArgs);
    }
    this._currentScale = newScale;
    if (!noScroll) {
      let page = this._currentPageNumber,
        dest;
      if (
        this._location &&
        !(this.isInPresentationMode || this.isChangingPresentationMode)