I might see if Susie wants to add to this, since she did a lot of the detailed work, but I guess what I would tell you is that even the accessibility act says that there should be nothing about us without us, so obviously consultation is important.
What we found when we looked at the consultations linked to Via was that it wasn't always clear how they considered the input. That doesn't mean they didn't, but that we just couldn't identify it.
I don't know if Susie wants to add more about some best practices.