Empy header cell for next columns if treeEnabled = true

The column content is set in onBeforeRowHeaderRender event handler. You'll need to modify it to exclude parent rows:

dp.onBeforeRowHeaderRender = (args) => {

    // skip parent rows
    if (args.row.children().length > 0) {
        return;
    }

    const beds = (count) => {
        return count + " bed" + (count > 1 ? "s" : "");
    };

    args.row.columns[1].html = beds(args.row.data.capacity);
    switch (args.row.data.status) {
        case "Dirty":
            args.row.cssClass = "status_dirty";
            break;
        case "Cleanup":
            args.row.cssClass = "status_cleanup";
            break;
    }

    args.row.columns[0].areas = [
        {right: 3, top: 3, width: 16, height: 16, cssClass: "area-menu", action: "ContextMenu", visibility: "Hover"}
    ];

};

Thank you.. it's working like magic :) we must more deep into documentation :) because is so huge of possibilities

Only for those.. which want also disable css border on parent row... need to comment out this in <style>

.scheduler_default_rowheadercol2 .scheduler_default_rowheader_inner {} and define own classes like is done in style like .status_dirty.scheduler_default_rowheadercol2 and add after must be in onBeforeRowHeaderRender