updating CommandLine.arguments on repeated 'open -a' commands

Wanted to add some basic scripting capabilities for an AppKit Swift application on macOS. I looked at adding AppleScript support (i.e. Cocoa Scripting) and it, frankly, hurts my head.

I then discovered that Swift provides for CommandLine.argc and Commandline.arguments. So, from Terminal, I can do

open -a myApp --args arg1 arg2 arg3

and sure enough, MyApp starts and CommandLine.arguments contain arg1, arg2, arg3 along w/ the first entry which is the fully resolved path of the executable. Great!

However, if myApp is already running when I execute

open -a myApp --args arg4

CommandLine.arguments are not updated and I get the same values as when I originally started the program (i.e. arg1, arg2, arg3 and not arg4).

So I added

func applicationShouldHandleReopen(_ sender: NSApplication, hasVisibleWindows flag: Bool) -> Bool { parseCommandLine(); return true}

to AppDelegate and while parseCommandLine is called for my second open -a command, it still points to the old CommandLine.arguments. Even tried returning false, but no difference.

Is there a way for CommandLine to be refreshed if myApp is already running?

Or a different way to get the same effect?