[TxMt] A more complete system for keyboard-based multiple selections?

I'd like to propose an extension to the multiple-selection functionality that makes it easier to use entirely from the keyboard. Currently you can perform a multiple selection using entirely the keyboard if you can use Find All (⌥⌘F). I think it would be nice if you could use the arrow keys to navigate as usual, then tap command (or some other key combo) to set a caret in the current location, keep navigating, set another caret, etc. Once you build up several carets you can begin editing via some other keystroke.

This would work kind of like TM1's rectangular selection using the option key. What do you all think?