Yes, the goal isn't to test that TinyMCE itself is operating in full, that's kind of expected as long as we use stable releases. Our customizations like "insert image" and "insert link" would be more valueable to test. And "insert multimedia" of course. Lower priority: "Insert macron", since that's a TinyMCE plugin we've written ourselves.

Catching the spell check sooner: We shouldn't rely on external services for test execution really, so testing the availability of such a service through Behat isn't ideal.