When DYAD gets minted by a Note holder, this is registered in the Notes metadata. Burning DYAD and withdrawing the underlying collateral (these two actions combined are considered redeeming) therefore also happens via Notes. When DYAD is burned by a Note holder, their minted balance goes down accordingly. Both minting and burning of DYAD is gated to Note holders. If DYAD is trading above or below peg in an external liquidity pool, an arbitrage opportunity opens up that is only available to Note holders.