In classical play, do GMs tend to resign in endgames like king+queen vs king+rook where the game can be won by the side with more material in under 50 moves, but only with good play? (I understand queen vs rook is a win in 31 in worst case, barring any immediate captures/checks which make it a draw. A computer can likely draw it out to 50 moves against a human, but another human might not.)
Queen vs rook isn't the only example - think of any pawnless endgame where the fastest forced mate is between 20 and 50 moves long.
On one hand I could see that it might be insulting to continue to play on with such a difference in material, where your opponent will clearly not fall for any skewer tactics and the endgame will be very long and very boring, but on the other hand I see the pragmatism in continuing play as long as there is a non-trivial chance of a draw.