I'm not a royalist and not sure on republic for us here in Australia but respect is more than due and not just for the Queen.
No apology is good enough, certainly no formal apology.
Once we knew you were partying on the night you made the Queen of the Commonwealth sit alone, due to restrictions you clearly thought to be a joke, you had no right to say sorry.
If you have jobs, if you haven't at least resigned, if you haven't gotten on your knees and begged to all of the people denied access to ill, dying or dead family and friends, not just the Queen, your pretty words have no meaning and you have no right to say them.
FALL ON YOUR SWORD, MAKE IT HAVE MEANING.