I was looking for some information on the site that might help for applications to the GRFP. I found JeffE's answer to an old question extremely useful. However, I noticed that some of the advice he gives appears to be somewhat outdated. For example, the answer claims that it is a very bad idea to provide more than 3 recommendations, since any extra recommendations will be ignored. However, the NSF site now states:
Applicants are required to submit three reference letters. There are five slots available for applicants to list reference writers. Applicants are strongly encouraged to utilize all available slots.
Have there been any other changes to the application criteria in the last few years that might invalidate any of the points in the old answer? Is there anything new to consider?