how to ensure that test continues until the page is done loading

The page I am testing is an SPA and relies heavily on Javascript for rendering. Is there a way to configure WPT to wait until all JS scripts are done executing? It seems that with the default settings WPT in IE11 ends the tests way too early.

Here is an example:
The URL under test is

When run with the default settings the tests end at around 2 seconds while the JS evaluation is still going on.

Full test report:

When run with minimum test running time set to 10 seconds (as suggested in another thread on this forum) the results are as expected.

Full test report:

Unless there is a way to wait until CPU usage is less than x % for y seconds, you could ask the devs to trigger some “keep-alive” requests.