A brief update: We gave up trying to use Selenium IDE to write our integration tests, and instead used the Selenium Python bindings for Selenium WebDriver.
With this approach, we can navigate to a URL and then use WebDriverWait
to detect a particular change in the DOM, e.g.
driver = webdriver.Firefox()
driver.get("/#/login")
WebDriverWait(driver, 10).until(
lambda driver: driver.find_element_by_css_selector("form.login").is_displayed())