Keyboard shortcut to open new finder window from same/current location?

This works for folders but not files… column view works best for this, other views have odd ideas as to which folder you really mean.

Navigate to your deeply-nested destination

Select the 'deepest' folder in the hierarchy, this will be your 'dupe point'.
Hold Cmd ⌘ then double-click the selected folder.
A brand new window will open in front, to the same location.

If you do this with a file, it will try to launch in its default app.
If you have more than one item selected before double-click, or have one item selected but double-click another… all selections will be actioned.