I did a quick search for this and didn't find it. I await to be proved wrong...
If you move and your opponent only has one possible move available, why not just make it automatically? It could speed up some end-games.
It would be providing material assistance; if someone could not spot that they could make a move, they might resign.
Discussed here have-the-option-to-allow-forced-moves-to-happen-automatically and here conditional-moves).
I did a quick search for this and didn't find it. I await to be proved wrong...
If you move and your opponent only has one possible move available, why not just make it automatically? It could speed up some end-games.