Workaround time!
Make your selection in the Key Editor and then
Transport - Locate selection start
Copy … or Cut
Transport - Enter Cursor Position
Up Arrow
Up Arrow
Paste
I don’t know if you’ve changed your Key Commands so I just wrote the names of the commands out instead.
Most of the lines are pretty obvious except the Enter Cursor Position thingie, maybe?
It’s a great tool for navigating with extra precision.
When you invoke it a little box in the middle of the screen appears.
Up Arrow increase the selected part of the position and Down Arrow decrease it, funnily enough.
Right Arrow and Left Arrow moves the selection to different parts of the position in bars and beats etc.
So in my example with hitting Up Arrow twice you move two whole bars to the right.
This is instantaneous so you can watch where the position cursor is in the project.
The beauty of it all is that the subdivisions are retained when you change the value with the arrow keys.
This means that if your located selection starts at 11.2.0.123 and you move the position two bars you will end up at 13.2.0.123 precisely.
When you have done this a few times it gets second nature.
Since the selection is in the clipboard of the computer you can move e.g. two more bars and paste again.
Same goes for closing the Key Editor and opening another Part on another Track in the Key Editor and paste again.
HTH
Now if we only also had a Lasso Tool: