KlekleLegacy wrote in post #57:
Would a «White to play and exact mate in x moves» work like this?
White to play and exact mate in 7 moves.
I think it is correct but this version looks a lot like a normal mate-in-7 with only mate-in-1 alternatives on the first move. To make the type different you need to see white struggle to avoid a shorter mate throughout the solution as e.g. in post #52. Here is a version of post #41 with an exact mate (hope it is correct!):
.
For example:
That's OK but actually you don't need a new puzzle since the one in post #52 is already perfect for this assignment! It does not end in stalemate but in a position where it is clear that white will have no further trouble avoiding checkmate. Just as the finish of an endgame study which often finishes in a winning position and not in checkmate.
If you use the "exact mate" format then it's more like a conventional mate-in-n problem with a precise length and an unavoidable checkmate!