Improvements to the keyboard shortcuts for "Go to previous/next keyframes..."

I have a couple of (I reckon) cool idea around the keyboard shortcuts for

"Go to previous/next keyframes (J / K);"
I use this shortcut it ALLLL day every day as I imagine many of us do, and I think we could
improve upon it quite easily.

Here are my thoughts:
1) If no layer is selected - functions as it does now.

2) If a layer is selected, j/k takes you to the prev/next keyframe of THAT LAYER ONLY.

3) Add modifiers for Transform specific keyframe jumps.
e.g. Something like SHIFT+P+K takes you to the next POSITION keyframe of a selected layer, OR, if no layer is selected the next possible position keyframe on the timeline.

I think this would be really useful and save a heap of time, especially in and around detailed character rigs where there are tonnes of keyframes in short succession.