The first exists. "Cursor keys move all carets". Which can be toggled.
Under Tools > Options
1) Editor > General
There are 2 checkboxes:
"Cursor keys move all carets" => which applies as default if carets have been set with mouse clicks (and modifier keys)
"Cursor keys move all carets (column select)" => which applies as default if carets have been set alt-shift-cursor keys.
2) KeyMap
There is a command in the Multicaret section to toggle this for the current multi-carets.
So if you selected, without setting that option, then you can apply it via a keystroke.
The 2nd requires multi-selection => which aren't implemented (yet).