If fade_time is used, particles would be flagged PEK_HIDE (depending on time settings), but since this is not respected in drawing in 2.8 yet the user would have no indication of them keys being hidden. Also doing this for hair doesnt make much sense anyways... Reviewers: jacqueslucke Maniphest Tasks: T70259 Differential Revision: https://developer.blender.org/D5901