After this clarification responder may then set the contract, or continue an asking bid sequence. Opener must raise to the grand slam if he holds the queen of trmps. It always works. This area is tricky and could be omitted. Sometimes you can identify more than one queen, but always the trump queen.
Responder can then place our contract very accurately.
Provided he has considered overall losing count and his covers in the early stages before asking for controls we won't get to high. After 3 we need the extra 3NT further relay to untangle the minors There is no 1st ask here. Direct 4 would have been a diamond shortage. A 27 point Grand on trump break or break or Jx out. It pays to take the plunge if your hand is suitable.