About #2 Wasn't so sure about typescript so I tested it to confirm that it worked. But in Python3, the default arguments are evaluated at module time loading if I am not mistaken. The following will display roughly the same timestamp

  from datetime import datetime
  import time

  print(datetime.utcnow())
  def show_ts(d=datetime.utcnow()):
      print(d)

  time.sleep(5)
  show_ts()

where as in TS, the 2nd one will be roughly 5s older:

  const now = Date.now();
  console.log(now);

  function logTs(d=Date.now()) {
     console.log(d);
  }

  setTimeout(()=> {
     logTs();
  }, 5000);