If you already know some of the language, you'll be pleased to know that, yes, there is a way to skip forward to the more advanced material.
When you're logged in, go to /user/set-level
- if you're studying Thai go to https://lingopolo.org/thai/user/set-level
- if you're studying French go to https://lingopolo.org/french/user/set-level
- if you're studying Dutch go to https://lingopolo.org/dutch/user/set-level