I don't think the vans are supposed to help with these issues either but I am interested to see what could be done to change some of these problems.
What, the peak traffic problem? There is a simple solution. Build more capacity. But you have to build it in multiple places. There has to be more capacity to get guests out of MK at peak times, but then there also has to be more capacity at the destination, which means more parking trams and more roads. Whether or not that makes sense would require a lot more study. But if it was easy to get to the TTC and easy to get from there to your offsite lodging, would more people stay offsite? If so, would spending more money to make it easier for people to spend less money at WDW be a good choice?
I do think they need more capacity at the end of the night, but I think there is a limit. If you could transport everyone at MK going to the TTC all at once, what would happen? They would sit in their cars anyway because you can't leave the TTC. So Disney spaces them out, mostly not by choice, by limiting the capacity to the TTC. The smart people don't go running for their cars after the fireworks, they stand and spend money or enjoy an extra ride or two. They aren't going anywhere anyway.
Now is there an issue with the transportation options? Sadly yes. The monorail is... unpredictable. The ferries are generally pretty good, but god awful slow, and the buses are as good as they are going to get at that time. You can't fit any more in the bus stops. But again, when all three are running, you get jammed up leaving the TTC anyway.
People need to realize we don't build for max capacity. It's too expensive. It's always going to be slow to leave at peak time, so have a strategy that doesn't involve leaving with everyone else. And if you have to leave with everyone else, just be patient. There isn't a way around it. Not at Disney, not at a football game, not at school pick up and drop off. This is part of life at peak traffic times everywhere. It has very little to do with Disney.
I will say by making HEA more of a projection show I think they are making the problem worse. You are drawing more people to the Main Street area, making it more logical for them to leave right after. Making the crush worse. They need to find a way to disburse the late night crowd, not concentrate it.