Surely the most problematic issue here is...
...why would the RF risk spending any time in the company of H & M when they know it's highly likely that a) they'll be super-sensitively looking for reasons to take offence, to confirm their own narrative and b) any perceived slights/gaffes will be carefully stored up and turned into a massive drama in either print or on international TV??
Whatever your view of the situation, if I was King C III or any other royal, I'd be damn wary of spending any time in their company - you certainly couldn't relax or let your guard down. So it's a vicious circle where they claim they want to be part of the family, but snitch on private conversations then claim they've been shunned. So the family don't want any contact with them.
No wonder Kate and M travelled in separate cars to the Queen's lying-in-state! I bet Sophie was briefed to just talk about the weather with Meghan and not be drawn into any other topics.
They are both drama queens, though, and love being victims. Whatever the rights and wrongs, their personalities are their worst enemies, I think. They need to act with dignity (despite problems - never wash family linen in public!) and not seek attention. But the boat has sailed on that.