Not entirely sure whether you’re trying to do something else here …

But when I wish to slip keyframes, I “Toggle Clip Keframes” (opt-t, or click on the icon in the bottom left of the timeline window), you can then drag all motion or filter keyframes in one go by clicking the green or blue bars in-between keyframes and dragging.

If you only wish to adjust certain types of keyframe, you can show/hide inidvidual keyframe types by right clicking on the green or blue bars. Hidden keyframes will not be affected by your adjustment.