FoldingText launcher written in JXA (JS for macOS Scripting Architecture). copy into your path and rename to whatever you want it to be (I use `ft`).

ft.js

#!/usr/bin/env osascript -l JavaScript
ObjC.import('AppKit')

function run(argv) {
  if (!(Application('FoldingText').running())) {
    $.NSWorkspace.sharedWorkspace.launchApplication('/Applications/FoldingText.app')
  }
  
  var ft = Application("FoldingText");
  argv.forEach(function (item) {
    var fpath = Path(item);
    ft.open(fpath);
  });
}