My understanding is that there is a stand alone version of Google Mapmaker (not the
mapmaker.com one). The RER forums do seem to be read more frequently by Google Employees which is a help. And once a month with a Google Contact is better than zero. :)
One of the most frustrating things about mapmaker is the incredibly long review times. People come in, it looks like nothing is happening and then don't bother coming back. That is why as far as I am concerned in Canada, for example, there should be an RER from each province who is active and can speed this process up in that province. Maybe even more from different parts of the province based upon how much there is to cover. Without the local knowledge the review process is going to get more and more difficult as the information becomes more and more detailed. It will also become harder to get the trust level needed to push through changes. Similarly other countries would be broken down by state or province with representation at more of a local level The new badge system at least indicates to other mappers that they are getting some where which is an improvement.
Now I know lots of people will jump in and say that this is already what is happening. What I am saying is that it is not happening enough.
Based on my trust level I can push through immediately most road and trail edits up to minor arteries. Some of the longer ones require approval, this would make sense since I always concentrated on small sections at a time.