Manually hidden toolView shown after calling addTools in async mode

I found another weird case similar to #1320 when using the asynchronous paper mode: After adding a toolsView to an element, I want to (conditionally) hide one of the toolViews (in this example the "Remove" button). This works as expected in the normal synchronous rendering mode, but fails if async: true is set in the paper options.

Here is a modified code from the Hello-world-example to reproduce the problem:

var graph = new joint.dia.Graph;

        var paper = new joint.dia.Paper({
            async: true,
            el: document.getElementById('myholder'),
            model: graph,
            width: 600,
            height: 100,
            gridSize: 1
        });

        var rect = new joint.shapes.standard.Rectangle();
        rect.position(100, 30);
        rect.resize(100, 40);
        rect.attr({
            body: {
                fill: 'blue'
            },
            label: {
                text: 'Hello',
                fill: 'white'
            }
        });
        rect.addTo(graph);

        var rect2 = rect.clone();
        rect2.translate(300, 0);
        rect2.attr('label/text', 'World!');
        rect2.addTo(graph);

        var link = new joint.shapes.standard.Link();
        link.source(rect);
        link.target(rect2);
        link.addTo(graph);

        const elementTools = new joint.dia.ToolsView({
            tools: [
                new joint.elementTools.Boundary({ focusOpacity: 0.5 }),
                new joint.elementTools.Remove({ offset: {x: -10, y: -10} })
            ]
        });

        paper.on('element:pointerdown', (elemView) => {
            elemView.addTools(elementTools);
            elementTools.tools[1].hide(); //only works with async: false
        });

In synchronous mode, the remove button is correctly hidden

whereas in asynchronous mode the results looks as follows

I've already looked into the code and suspect https://github.com/clientIO/joint/blob/master/src/dia/ToolsView.mjs#L60 or https://github.com/clientIO/joint/blob/master/src/dia/ToolsView.mjs#L52 to cause the problem as this code might get executed after the manual hiding. A solution might be to (re)set all _visible flags of the toolViews to true directly (synchronously) when calling addTools.

Start with src/dia/ToolsView.mjs around lines 52 and 60, then reproduce the example using Paper with async: true and compare it with synchronous rendering. Verify that hiding elementTools.tools[1] after addTools remains effective in asynchronous mode; done means the Remove tool stays hidden.