I think you can adjust (recline) the seat more by wedging towels/something firm (my DH wants to get high density foam) under it. We were having a play with ours and I think that is what they suggested in the book? That reclines it more, but it still sits flat. We will have another look and just see how it goes. I haven't read it myself so not certain.

I think how high it sits depends on the amount of incline on the seat itself too.