Solution 1 (recommended)

Apple updated its Technical Notes to indicate that since 10.12.2, macOS includes version 7.3p1 of OpenSSH and its new behaviors.

In ~/.ssh create config file with the following content:

Host * (asterisk for all hosts or add specific host)
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile <key> (e.g. ~/.ssh/userKey)

find . -printf "%T@ %Tc %p\n" | sort -n

printf arguments from man find:

    %Tk: File's last modification time in the format specified by k.

    @: seconds since Jan. 1, 1970, 00:00 GMT, with fractional part.

    c: locale's date and time (Sat Nov 04 12:02:33 EST 1989).

    %p: File's name.

Add this to your user's ~/.gitconfig under [alias] to make it globally available:

lsch = "!f() { git diff --name-status -r "HEAD~$1"; }; f"

You can invoke this to retrieve all affected files in the last 7 commits like so:

$ git lsch 7