{ The repetition of the same verb }
You’re lucky that I found you when I did.
Tu as eu de la chance que je t'aie trouvé quand je t'ai trouvé.
In English, you’ll never say: "You’re lucky that I found you when I found you", since this kind of repetition is shunned. So I suppose that my suggested French sentence above needs to be altered accordingly, though I’m not sure how.
The same goes for the following:
Thank you so much for coming with us as far as you did. {You never say "as far as you came"}
Un grand merci pour nous avoir accompagnés aussi loin que... ???