If you set trust depth to 2, you will likely be ended up trusting the feedback of most of the forum users.
That's wrong, as shown by my Trust depth viewer.
When we set it 0, we are only trusting feedback directly from our custom trust list. When we set it 1, we trust their trust list and with setting it 2, aren't we going more deep? That's how I used to know the system works. My bad if I was in the wrong all these days.
If that's true but you don't have a lot of people in trust depth viewer, I think I shouldn't use the term "a lot of people use the system".
That's also wrong: the old feedback system largely worked the same.
We had feedback score which wasn't simply the number of positive, negative and neutral feedbacks. It was a score calculated by an algorithm which many found complicated. That's what I have observed in the past.
You're going to have to provide some evidence for this.
Checking the number of custom trust list now vs old would be the evidence but I don't have it.