A couple of thoughts on the latch issue.
1. Has anyone factored in the weight of the tongue pressing down on the ball, countering the force trying to pull the latch into the ball?
2. Since the ball does not rotate in the coupler (or very minimally at worst, not enough to create a wear issue), wear on the latch won't be an issue. Assuming pressure from the tongue weight does not pull the ball away from the latch (I'm thinking it will), the only time the full pressure from the hitch will be against the latch would be when it is static. As the trailer moves forward, any pressure on the latch (assuming there is any) should be reduced or removed from the latch.
3. (OK, I lied about only a couple of thoughts.) In any kind of hitch, the latch would have to take the entire force from the tow vehicle when backing unless the tongue weight is countering some or all of that force by forcing the dome of the coupler onto the upper curvature of the ball (as, again, I feel it does). Since hitches don't normally break when backing, I feel the concerns for the hitch latch when using the Anderson WDH are exaggerated.
I don't have a trailer handy to do this right now but has anyone tried to back a trailer without the latch being engaged? That would give an idea of how much effect tongue weight would have on countering the sideways force being exerted.