The default when creating a component group when viewing your page seems to be a plus symbol to expand the group. However, I have seen pages elsewhere clearly using Status Page, with the drop down arrow instead.
How to I also use the drop down arrow?
Are there any other customisations available to change the format of groups?
While we don't provide support for code customizations - to point you in the right direction, you would probably want to use JQuery or Javascipt to replace the '.fa-plus-square-o' Font Awesome class with another CSS class that displays a dropdown arrow, like the <i class="fa-solid fa-caret-down"></i>, for example.