I think the biggest problem is the way the gates are laid out. All the time I see how difficult it is for GS to pre board when the group 1 lane is full of people. Now imagine a family trying to squeeze through that with strollers and kids and backpacks. Maybe they should use lane 5 for pre boards and tell group 5 people to not get up and fill the lane. Or create a pre board area right by the gate and if you want to pre board you have to be accepted into that area no later than 15 minutes before general boarding. If you aren't there, you board with your regular group.