Update donor context if order assigned

Good point. This seems quite important to me in general. I can see it's less important specifically for a site where the orders are almost all placed by authenticated users.

A related wrinkle is that sites will likely want to link anonymous checkout declarations with donor by order email even if the order is never assigned.

The "related contexts" stuff could help with that in theory but it's a bit heavyweight.

Without this, anonymous declarations will fail to arrive on the user, so I've altered the issue settings.

I'm happy for you to say it's not a road-map priority. Even so, I feel we should have these clearer issue settings to help us or anyone else see the status in the future.