Seven players, round two, and you speak third. Nobody has said "Dapp!".
Your hand
Do you claim the Dapp?
Answer
Pass. The XVI would need six other Taroks to be a trump stop, and you hold two, so the duty does not bind you. Without a trump stop, pass. Twelve new cards are tempting, but one Tarok from the XV up gives the exchange little to rebuild around.
Rule: With a trump stop on the ladder, the trump-stop duty can force you to bid, and that is also the hand worth claiming voluntarily, because the twelve-card exchange rebuilds the hand around the trump stop; without a trump stop, pass.