Did you solve the issue? My solution partially works for my case, hence I am still looking for a definitive solution.

So, define the delegate in the HorizontalHeaderView as suggested in the question you've mentioned.

In the TableView, implement a columnWidthProvider function such as the one bellow:

columnWidthProvider: function(column) {
                if (!isColumnLoaded(column))
                    return -1;
                let headerWidth = horizontalHeader.implicitColumnWidth(column);
                let dataWidth = tableView.implicitColumnWidth(column);
                // limit the minimum width to the header width
                let columnWidth = Math.max(headerWidth, dataWidth);
                // and optionally limit the maximum width to 200
                return Math.min(columnWidth, 200);
            }

The problem with this solution is that it prevents manual resizing of the columns.