“leading to the king being good to Yidden for the remaining 46 years of his monarchy… Do you really think such shailos should go to the most esteemed litvishe poskim who dealt with Russian kings and comissars or to London beisdin who are boke in Anglican kings marriage minhagim from the time of Henry the 8th?”
He’s not a real king. He could be a neo-Nazi and it wouldn’t matter because he can’t actually do anything to us. I’m not taking a position on whether or not there’s a valid heter, but if there is, it’s definitely not to appease the monarchy that’s purely symbolic.
Since you bring up Henry the 8th, presumably because he started the Anglican Church, you probably know that he made the reigning monarch the head of the church as a replacement for the pope. Now that the monarchy has no political relevance, being head of the church is the primary significance of the monarch. Thus, people need to understand that this ceremony is a lot more comparable to anointing a new pope than it is to inaugurating a new president.