Jim, as long as your PDF's are done as an 8.5" x 11" at 300dpi(no color or grayscale) and your certifier has a program that can edit the info needed on the map, then he can use your PDF's. I don't know if he uses your PDF's.
Your certifier(Mike Wickiser)does sends me PDF's that I convert to the correct size and format for the USATF site. A measurer doesn't need to worry about 300dpi with png's as the Certifier is the one who needs to understand this. However, a Certifier does need to make sure the PDF's are of the proper dimensions and 300dpi.
There are about 15 Certifier's on the East that are now sending me their Certifications electronically. Some send as PDF's and others send me the proper form for the USATF site(the 300dpi stuff as a png). If any East Certifers that haven't done this and are interested in electronic submissions please contact me.