The other way if you want double/half tempo is to apply stretch tool on midi event. You can hold Ctrl to disable snap on grid. Lot of people asked for warp tool in midi editor but still no luck…
Good to know it’s possible.
Would be nice if it becomes possible someday in the piano roll though as linked above
Yes.! Would be really good - exactly as here; the Key Editor should rule as far as workflow is concerned.!