How many render operations does act() support?

Question

I am using act function from library https://testing-library.com/docs/react-testing-library/intro/.

At this point I have something like this:

 await act(async () => {
        page = renderPage([mockData, mockData2]);
      });
      await act(async () => {
        onLoadSuccessFn?.({ numPages: 15 } as PDFDocumentProxy);
        await waitForExpect(() => {
          expect(page?.find('[id*="idToBeFound"]')).toBeTruthy();
        });
      });

In the first act I am waiting for the page/component to be rendered. In the second act I am calling onLoadSuccessFn, which will trigger the rendering of another component.

However, if I group the 2 pieces of code(render of the component and function call described above) under the same act, my test will fail, basically because only one statement will be executed(out of the 2)