Moving all particle keys at once?

I’m developing what’s going to be a relatively complex keyed particle system. Problem is, in a regular keyed system, in most software where there’s a timeline you can move one key and subsequent keys will move automatically along the timeline to accommodate. This is useful when I’ve got the framework of an animation but just want to make a part of the animation longer or shorter.

Even in Blender I know you can do this for regular animations. But is this possible for keyed particle systems, without having to change each and every keyed point by manually working out and changing the frame number?

It’s easier to explain in a video