What is the correct Suitescript 2.0 method to disable a column

HI

I have a userevent script with a before record load function.

The function is working correctly for the most part other than the following:

 var rateColumn = form.getSublist({ id: "item" }).getField({ id: "rate" });
      rateColumn.updateDisplayType({ displayType: "disabled" });
      log.debug(rateColumn);

      var plColumn = form.getSublist({ id: "item" }).getField({ id: "price" });
      plColumn.updateDisplayType({ displayType: "disabled" });

      var amtColumn = form
        .getSublist({ id: "item" })
        .getField({ id: "amount" });
      amtColumn.updateDisplayType({ displayType: "disabled" });

      var grossAmtColumn = form
        .getSublist({ id: "item" })
        .getField({ id: "grossamt" });
      grossAmtColumn.updateDisplayType({ displayType: "disabled" });

When the displayType is set to disabled, this does nothing.

However, if it is set to 'hidden' that works correctly.