For electrical outlets and sockets, there is a parameter to offset them in elevation in front of the furniture. Since the furniture is in most cases 600–650 mm deep, I think it would be a good idea to set 700 mm as the default value in the families.
I think it would be useful to have a way to color-code different socket types in plan. In many projects, there are visible sockets that are design-relevant and more expensive, while sockets hidden behind furniture can be treated differently and are often much cheaper. I believe this could be handled with an instance parameter, which could then be used in a filter to apply different colors.