I want to keyframe only the x-value of the rotation while the y and z are being animated independently. (If you want to know why, I'm making the camera continuously revolve about the z-axis at the center of the scene and using the x rotation to change the polar angle at one part.)
I can achieve the effect using the dope sheet to delete the y and z keyframes after I use the I
hotkey to create a keyframe for all three values, which is honestly not so bad, but it seems like there should be a Ctrl + I
or some other way to have more fine control of keyframes without having to open the dope sheet.