script interpolation for object [QUESTION]

Hi guys, has I know that we use external string values in script function by assigning the variable with value in custom triats. but I tried to pass the object or array. I didn't get the correct values. i really stuck on it can anyone please help me.

my traits:-

 comps.addType(buttonName, {
      model: defaultModel.extend({
        defaults: Object.assign({}, defaultModel.prototype.defaults, {
          draggable: '*',
          droppable: false,
          myModelCount: 5,
          myModelPropName: { name: 'age' },
          script: function () {
            const first = '{[ myModelPropName ]}';
            const test = JSON.stringify(first);
            console.log('screens global variable ----333--  ', JSON.parse(test));
            const mycount = '{[ myModelCount ]}';
            const initAgGrid = () => {

              console.log('inside of ----- ', mycount);
              // const columnDefs = [];
              for (let i = 0; i < 5; i++) {
                console.log(' for loopppp  ----- ', i);
              }
              const columnDefs = [
                {
                  headerName: 'A',
                  field: 'a',
                  sortable: true,
                  colId: 'col1_id'
                },
                {
                  headerName: 'B',
                  field: 'b.name',
                  sortable: true,
                  colId: 'col2_id'
                },
                {
                  headerName: 'C',
                  field: 'c.name',
                  sortable: true,
                  colId: 'col3_id'
                },
                {
                  headerName: 'D',
                  field: 'd.name',
                  sortable: true,
                  colId: 'col4_id'
                },
                {
                  headerName: 'E',
                  field: 'e.name',
                  sortable: true,
                  colId: 'col5_id'
                }
              ];

              function createRowData() {
                const rowData = [];
                for (let i = 0; i < 100; i++) {
                  // create sample row item
                  const rowItem = {
                    // is is simple
                    a: 'aa' + Math.floor(Math.random() * 10000),
                    // but b, c, d and e are all complex objects
                    b: {
                      name: 'bb' + Math.floor(Math.random() * 10000)
                    },
                    c: {
                      name: 'cc' + Math.floor(Math.random() * 10000)
                    },
                    d: {
                      name: 'dd' + Math.floor(Math.random() * 10000)
                    },
                    e: {
                      name: 'ee' + Math.floor(Math.random() * 10000)
                    },
                    f: {
                      name: 'ee' + Math.floor(Math.random() * 10000)
                    }
                  };
                  rowData.push(rowItem);
                }
                return rowData;
              }
              this.gridOptions = {
                defaultColDef: {
                  editable: true
                },
                columnDefs: columnDefs,
                rowData: createRowData(),
                components: {
                  boldRenderer: function (params) {
                    return '<b>' + params.value.name + '</b>';
                  }
                },
                onGridReady: function (params) {
                  params.api.sizeColumnsToFit();

                  window.addEventListener('resize', function () {
                    setTimeout(function () {
                      params.api.sizeColumnsToFit();
                    });
                  });
                },
                paginationAutoPageSize: true,
                pagination: true,
              };
              const gridDiv = document.querySelector('#myGrid');
              // tslint:disable-next-line:no-unused-expression
              new agGrid.Grid(gridDiv, this.gridOptions);
              this.gridOptions.cacheQuickFilter = false;
              this.gridOptions.api.sizeColumnsToFit();
            };
            let exists = false;
            const url = 'https://unpkg.com/[email protected]/dist/ag-grid-community.min.js';
            const scripts = document.getElementsByTagName('script');
            for (let i = scripts.length; i--;) {
              if (scripts[i].src === url) {
                exists = true;
              }
            }
            if (exists) {
              initAgGrid();
            } else {
              const script = document.createElement('script');
              script.onload = initAgGrid;
              script.src = url;
              document.body.appendChild(script);
            }
          },
          traits: [{}]
}),

screenshots

in the above screenshot. myModelCount value are printed but the myModelPropName value is shows [object, object] inside of script function.