The insert key operator allowed to insert a keyframe on all selected FCurves and on the Active FCurve at cursor value. But it didn't allow to insert a keyframe only on the active FCurve. This patch adds that. It is available in the redo panel and under Key->Insert Keyframes (which can also be called with the I hotkey) Pull Request: https://projects.blender.org/blender/blender/pulls/106307